Substituted triazoles and methods relating thereto

ABSTRACT

Substituted 1,2,3-triazole compounds are disclosed which have utility in the treatment of a variety of neurological disorders. The compounds provided herein have the general structure: 
     
       
         
         
             
             
         
       
     
     wherein R 1 , R 2 , R 3  and n are as defined herein, including stereoisomers, esters, solvates and pharmaceutically acceptable salts thereof. Also disclosed are compositions containing a compound provided herein in combination with a pharmaceutically acceptable carrier, as well as methods relating to the use thereof for treating neurological disorders in a subject in need thereof.

BACKGROUND

1. Technical Field

This disclosure relates generally to substituted 1,2,3-triazolecompounds, to processes and intermediates used in their preparation, tocompositions containing them and to methods of treating neurologicaldisorders by administration of such compounds to a warm-blooded animalin need thereof.

2. Description of the Related Art

Essential tremor (ET) is one of the more common tremor disorders and oneof the more common neurological diseases. While the disease is oftencalled “benign”, this postural and/or kinetic tremor frequently causesdifficulty with everyday tasks such as writing, pouring and eating. EThas a prevalence comparable to that of epilepsy and greater than bothParkinson's disease and Alzheimer's disease. The incidence of ET riseswith increasing age and a family history of ET appears to correlate witha younger onset of disease. Pharmacological treatments of this disorderare limited due to variable effectiveness, occurrence of side effectsand lack of understanding of the pathophysiology of the disease.

ET has variable clinical expression characterized by a postural and/orkinetic tremor with a frequency range between 4 and 12 Hz. The tremorfrequency generally decreases over time while amplitude increases.Approximately 90% of patients have tremor in their upper extremities,30% have a head tremor, 20% voice tremor, 10% face or jaw tremor and 10%lower body tremor. Additionally, recent studies indicate higher rates ofmild cognitive changes, depression, anxiety, social phobias andolfactory and hearing deficits in ET patients compared to normalcontrols (see, e.g., Zesiewicz et al., Neuropsychiatric Disease andTreatment, 2010:6, 401-408).

The oldest anti-tremorgenic agent in the management of ET is ethanol.While showing some beneficial effects, this therapy is impractical dueto addiction issues and serious drawbacks with long-term ethanol use(see, e.g., Iseri et al., Neuropharmacology, 2011, 61:715-723).

Although many medications have been tested, the pharmacologicaltreatment of ET is not optimal. Two medications are consideredfirst-line treatments: propranolol, a nonselective beta blocker which isthe only FDA approved agent for ET; and primidone, an antiepilepticdrug. In addition to side effects which include bronchoconstriction,bradycardia, hypotension, depression and fatigue for propranolol andsedation, dizziness, fatigue, nausea and depression for primidone (see,e.g., Abboud et al., Cleveland Clinic Journal of Medicine, 201178:12:821-828), neither drug reduces tremor levels to asymptomaticlevels nor is effective in more than about half of patients withdisease.

In addition to the first-line treatments for ET noted above, over thelast decade several other therapies have been studied, most of which areolder drugs repurposed for ET such as antiepileptic agents, gabapentin,topiramate, zonisamide, levitiracetam, phenobarbital, pregabalin andlacosamide; calcium antagonists flunarizine and nicarpine;benzodiazepines such as alprazolam; antidepressant mirtazapine; andagents such as sodium oxybate, T-2000 and 1-octanol. Further botulinumtoxin injection has been the subject of several small studies and may beuseful for intractable head and voice tremor (see, e.g., Shill, ClinicalMedicine: Therapeutics (2009) 1: 613-620, Sadeghi et al., Drugs 2010;70(17):2215-2228).

Surgical procedures may also provide treatment for severe and refractoryET. Deep Brain Stimulation of the ventral intermediate thalamus involvessurgery to implant an electrode and a pulse generator. Thalamotomy is astereotactic procedure that creates a lesion in the ventral intermediatenucleus of the thalamus. Side effects and adverse events limit thissurgery to patients who are not responsive to pharmacotherapy (see,e.g., Zesiewicz et al., Neuropsychiatric Disease and Treatment, (2010)6:401-408).

Epilepsy is a brain disorder characterized by periodic and unpredictableseizures. The behavioral manifestations of epileptic seizures in humanpatients range from mild twitching of an extremity to loss ofconsciousness and uncontrollable convulsions. Up to 1% of the populationis afflicted, making epilepsy one of the most common neurologicalproblems and a considerable economic burden on society. Despite theconsiderable progress in our understanding of the pathophysiology andpharmacotherapy of seizures and epilepsy, the cellular basis of humanepilepsy remains an enigma. In the absence of etiological understanding,approaches to pharmacotherapy have been directed to the control ofsymptoms; namely, the suppression of seizures. More concerning is thatcurrent antiepileptic drugs do not halt the underlying naturalprogression of the disorder.

Over the years, there has been considerable success in the developmentof novel antiepileptic drugs (AED) along with new improved formulations.These include older “first generation” drugs such as carbamazepine,phenobarbital, valproic acid and newer, “second generation” drugs suchas lamotrigine, vigabatrin, tiagabine, topiramate, gabapentin andlevetiracetam (see, e.g., Brazil et al., Ann. Rev. Med., 1998,49:135-162; McCabe P H., Expert Opinion. Pharmacother., 2000,1:633-674]. The selection of an antiepileptic drug for treatment ispredicated on its efficacy for the specific type of seizures,tolerability and safety (see, e.g., Regesta et al., Epilepsy Res., 1999,34:109-122; Kwan et al., Engl. J. Med., 2000, 342:314-319).

Status epilepticus (SE) is a life threatening condition characterized bya prolonged state of continuous convulsions resulting in significantmorbidity and mortality. SE is defined as seizure activity lasting for30 minutes or longer without regaining consciousness. Treatment shouldbe initiated promptly since prolonged SE may result in death,progressive brain damage or develop into the difficult to treatrefractory SE. As many as 200,000 people are affected in the U.S.annually, with as many as 55,000 deaths. Causes of SE include both acutehealth problems such as stroke, metabolic disturbances, infections, headtrauma and drug interactions and chronic processes such as pre-existingepilepsy, discontinuation of drug therapy and central nervous systemtumors (see, e.g., Deshpande et al., Front Neurol (2014, 5:11).

SE is categorized as convulsant or nonconvulsant, both of which requireprompt treatment to prevent death and brain injury. The pathophysiologyof SE is not clearly understood. After medical stabilization of thepatient a first line treatment involves intravenous or intramuscularadministration of a benzodiazepine such as midazolam, diazepam orlorazepam. Second line therapy involves the additional administration ofphenytoin, fosphenytoin, phenobarbital or valproic acid. Approximately40% of SE cases do not resolve to this treatment and are termedrefractory. Refractory SE is generally treated with anesthetics such aspropofol or phenobarbital. (see, e.g., Reddy et al., Int. J. Mol. Sci.2013, 14:18284-318).

Nerve agents inhibit acetylcholinesterase resulting in elevatedacetylcholine levels in the nervous system. Ensuing cardiorespiratorydepression and status epilepticus may lead to death or brain damage inaffected individuals (see, e.g., Apland et al., J Pharmacol Exp Ther2013, 344:133-40).

While significant strides have been made in this field, a need remainsfor small molecules effective in the treatment of neurological disordersand diseases, especially essential tremor, epilepsy, status epilepticus,and/or nerve agent exposure. These small molecules may reduce some ofthe side effects and limitations of current drug therapies such astreatment of refractory patients, reduced sedation, cognitive andbehavioral effects, drug/drug interactions, andteratogenicity/genotoxicity concerns. The present disclosure fulfillsthese needs and provides other related advantages.

BRIEF SUMMARY

In brief, this invention is generally directed to 1,2,3-triazoleanalogs, as well as to methods for their preparation and use, and topharmaceutical compositions containing such compounds. Morespecifically, the 1,2,3-triazole analogs described herein are compoundshaving the following structure (A):

including stereoisomers, esters, solvates and pharmaceuticallyacceptable salts thereof, wherein R₁, R₂, R₃, and n are as definedherein.

In another embodiment, a pharmaceutical composition is providedcomprising any one of the compounds described above and herein incombination with a pharmaceutically acceptable carrier and/or diluent.

In another embodiment, methods are provided for treating a condition ina subject in need thereof, wherein the condition is essential tremor,epilepsy, status epilepticus, and/or nerve agent exposure byadministering to the subject a compound as described above and herein(or pharmaceutically composition comprising the compound).

In another embodiment, a method is provided for treating a neurologicalcondition or disorder to a subject in need thereof by administering tothe subject a compound as described above and herein (orpharmaceutically composition comprising the compound).

These and other aspects of the invention will be apparent upon referenceto the following detailed description. To this end, various referencesare set forth herein which describe in more detail certain backgroundinformation, procedures, compounds and/or compositions, and are eachhereby incorporated by reference in their entirety.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments.However, one skilled in the art will understand that the presentcompounds may be made and used without these details. In otherinstances, well-known structures have not been shown or described indetail to avoid unnecessarily obscuring descriptions of the embodiments.Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, suchas, “comprises” and “comprising,” are to be construed in an open,inclusive sense, that is, as “including, but not limited to.” Inaddition, the term “comprising” (and related terms such as “comprise” or“comprises” or “having” or “including”) is not intended to exclude thatin other certain embodiments, for example, an embodiment of anycomposition of matter, composition, method, or process, or the like,described herein, may “consist of” or “consist essentially of” thedescribed features. Headings provided herein are for convenience onlyand do not interpret the scope or meaning of the claimed embodiments.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

Also, as used in this specification and the appended claims, thesingular forms “a,” “an,” and “the” include plural referents unless thecontent clearly dictates otherwise. Thus, for example, reference to “anon-human animal” may refer to one or more non-human animals, or aplurality of such animals, and reference to “a cell” or “the cell”includes reference to one or more cells and equivalents thereof (e.g.,plurality of cells) known to those skilled in the art, and so forth.When steps of a method are described or claimed, and the steps aredescribed as occurring in a particular order, the description of a firststep occurring (or being performed) “prior to” (i.e., before) a secondstep has the same meaning if rewritten to state that the second stepoccurs (or is performed) “subsequent” to the first step. The term“about” when referring to a number or a numerical range means that thenumber or numerical range referred to is an approximation withinexperimental variability (or within statistical experimental error), andthus the number or numerical range may vary between 1% and 15% of thestated number or numerical range. It should also be noted that the term“or” is generally employed in its sense including “and/or” unless thecontent clearly dictates otherwise. The term, “at least one,” forexample, when referring to at least one compound or to at least onecomposition, has the same meaning and understanding as the term, “one ormore.”

Terms not specifically defined herein should be given the meanings thatwould be given to them by one of skill in the art in light of thedisclosure and the context. As used in the specification, however,unless specified to the contrary, the terms have the meaning indicated.

Described herein are compounds useful for treating neurological diseasesand/or disorders, which compounds have the following structure (A):

or a stereoisomer, ester, solvate, or pharmaceutically acceptable saltthereof, wherein:

R₁ is H or C₁₋₄alkyl;

R₂ is C₁₋₄alkyl, —C(═O)OR₄, —C(═O)—C₁₋₆alkanediyl-NH₂, —C(═O)NR₅R₅, or—C(═O)R₆, wherein said C₁₋₆alkanediyl is optionally substituted with agroup selected from —NH—C(═NH)NH₂, —CO₂H, —CO₂CH₃, —SH, —C(═O)NH₂, —NH₂,—SCH₃, phenyl, —OH, —OC₁₋₄alkyl, 4-hydroxy-phenyl, cyclohexyl,imidazolyl, and indolyl;

or R₁ and R₂ taken together with the N to which they are attached, forma 5-6 member nonaromatic heterocycle wherein the 5-6 member nonaromaticheterocycle may be substituted with 0-3 R₄;

R₃ at each occurrence is independently Cl, F, —OC₁₋₄alkyl ortrifluoromethyl;

R₄ at each occurrence is independently C₁₋₄alkyl;

R₅ at each occurrence is independently H or C₁₋₄alkyl;

R₆ is C₁₋₄alkyl, 5-6 member nonaromatic heterocycle, or 5-6 memberheterocycleC₁₋₄alkyl wherein 5-6 member heterocycleC₁₋₄alkyl isoptionally substituted with OH, Cl, F, C₁₋₄alkyl, —OC₁₋₄alkyl ortrifluoromethyl; and

n is 0-3.

In one embodiment of structure (A), R₁ is C₁₋₄alkyl.

In one embodiment of structure (A), R₁ is methyl.

In one embodiment of structure (A), R₁ is ethyl.

In one embodiment of structure (A), R₁ is H.

In one embodiment of structure (A), R₁ and R₂ are both C₁₋₄alkyl.

In one embodiment of structure (A), R₂ is C₁₋₄alkyl.

In one embodiment of structure (A), R₂ is —C(═O)OR₄.

In one embodiment of structure (A), R₂ is —C(═O)—C₁₋₆alkanediyl-NH₂. Inmore specific embodiments, C₁₋₆alkanediyl is optionally substituted witha group selected from —NH—C(═NH)NH₂, —CO₂H, —CO₂ CH₃, —SH, —C(═O)NH₂,—NH₂, —SCH₃, phenyl, —OH, —OC₁₋₄alkyl, 4-hydroxy-phenyl, cyclohexyl,imidazolyl, and indolyl. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —NH—C(═NH)NH₂. In a certain embodiment, C₁₋₆alkanediylis substituted with —CO₂H. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —CO₂CH₃. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —SH. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —C(═O)NH₂. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —NH₂. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —SCH₃. In a certain embodiment, C₁₋₆alkanediyl issubstituted with phenyl. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —OH. In a certain embodiment, C₁₋₆alkanediyl issubstituted with —OC₁₋₄alkyl. In a certain embodiment, C₁₋₆alkanediyl issubstituted with 4-hydroxy-phenyl. In a certain embodiment,C₁₋₆alkanediyl is substituted with cyclohexyl. In a certain embodiment,C₁₋₆alkanediyl is substituted with imidazolyl. In a certain embodiment,C₁₋₆alkanediyl is substituted with indolyl.

In one embodiment of structure (A), R₂ is —C(═O)NR₅R₅.

In one embodiment of structure (A), R₂ is —C(═O)R₆.

In one embodiment of structure (A), R₃ is Cl.

In one embodiment of structure (A), R₃ is F.

In one embodiment of structure (A), R₃ is C₁₋₄alkyl.

In one embodiment of structure (A), R₃ is —OC₁₋₄alkyl.

In one embodiment of structure (A), R₃ is trifluoromethyl

In one embodiment of structure (A), R₄ is methyl.

In one embodiment of structure (A), R₄ is ethyl.

In one embodiment of structure (A), R₅ is H.

In one embodiment of structure (A), R₅ is C₁₋₄alkyl.

In one embodiment of structure (A), R₆ is C₁₋₄alkyl.

In one embodiment of structure (A), R₆ is a 5-6 member nonaromaticheterocycle.

In one embodiment of structure (A), R₆ is a 5-6 memberheterocycleC₁₋₄alkyl wherein 5-6 member heterocycleC₁₋₄alkyl isoptionally substituted with OH, Cl, F, C₁₋₄alkyl, —OC₁₋₄alkyl ortrifluoromethyl. In a more specific embodiment, the 5-6 memberheterocycleC₁₋₄alkyl is substituted with OH. In a particular embodiment,the 5-6 member heterocycleC₁₋₄alkyl is substituted with Cl, F, ortrifluoromethyl. In a particular embodiment, the 5-6 memberheterocycleC₁₋₄alkyl is substituted with C₁₋₄alkyl or —OC₁₋₄alkyl.

In one embodiment of structure (A), n=1.

In one embodiment of structure (A), n=2.

In one embodiment of structure (A), n=3.

In one embodiment of structure (A), R₁ and R₂ are taken together withthe N to which they are attached to form a 5-6 member nonaromaticheterocycle wherein the 5-6 member nonaromatic heterocycle may besubstituted with 0-3 R₄, as shown in structure (B):

or a stereoisomer, ester, solvate, and pharmaceutically acceptable saltthereof; wherein R₃ and R₄ and n are as defined above for structure (A).

In one embodiment of structure (B), the 5-6 member nonaromaticheterocycle further comprises at least one other heteroatom selectedfrom N, S, and O, or further comprises at least one other heteroatomselected from N and O.

In one embodiment of structure (B), n is 1.

In one embodiment of structure (B), n is 1 and R₃ is F or Cl.

In one embodiment of structure (B), n is 1 and R₃ is F.

In one embodiment of structure (B), n is 1 and R₃ is Cl.

In one embodiment of structure (B), n is 1 and R₃ is C₁₋₄alkyl.

In one embodiment of structure (B), n is 1 and R₃ is —OC₁₋₄alkyl.

In one embodiment of structure (B), n is 1 and R₃ is trifluoromethyl.

In one embodiment of structure (B), n is 2.

In one embodiment of structure (B), n is 2 and R₃ at each occurrence isF.

In one embodiment of structure (B), n is 1 and R₄ is methyl.

In one embodiment of structure (B), n is 1 and R₄ is ethyl.

In one embodiment of structure (B), the 5-6 member nonaromaticheterocycle (i.e., R₁ and R₂ taken together) is piperazine.

In one embodiment of structure (B), the 5-6 member nonaromaticheterocycle (i.e., R₁ and R₂ taken together) is morpholine.

In one embodiment of structure (B), the 5-6 member nonaromaticheterocycle (i.e., R₁ and R₂ taken together) is piperizine.

In one embodiment of structure (B), the 5-6 member nonaromaticheterocycle (i.e., R₁ and R₂ taken together) is oxazolidine.

In one embodiment of structure (B), the 5-6 member nonaromaticheterocycle (i.e., R₁ and R₂ taken together) is pyrrolidine.

In certain specific embodiments, the compound is selected from one ofthe following compounds, including pharmaceutically acceptable saltsthereof:

-   (2    S)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide;-   (2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide;-   (3    S)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide;-   (3R)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide;-   (2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-methoxypropanamide;-   (2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide;-   N-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-3-pyridin-3-yl-propionamide;-   3-(3-chlorophenyl)-N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}propanamide;-   (2S)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-2-(2-oxopyrrolidin-1-yl)butanamide;-   [1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine;-   [1-benzyl-1H-[1,2,3]triazol-4-yl]-dimethyl-amine;-   4-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine;-   1-[(2,6-difluorophenyl)methyl]-4-(pyrrolidin-1-yl)-1H-1,2,3-triazole;-   1-[(2,6-difluorophenyl)methyl]-N-methyl-1H-1,2,3-triazol-4-amine;-   1-[(2,6-difluorophenyl)methyl]-N-ethyl-1H-1,2,3-triazol-4-amine;-   2-({1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}amino)ethan-1-ol;-   1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}pyrrolidin-2-one;-   3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1,3-oxazolidin-2-one;    or-   1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}imidazolidin-2-one.

Certain chemical structures presented herein, particularly in thecontext of the examples section, may not depict all hydrogen atoms. Forexample, “—NH₂” (i.e., an amine group) may be depicted as “—N” (i.e.,absent two hydrogen atoms), a divalent amine (“—NH”—) may be depicted as—“N”— (i.e., absent one hydrogen atom), and an alcohol (“—OH”) may bedepicted as “—O” (i.e., absent one hydrogen atoms). These and othershorthand notations are well understood be one skilled in this field.

Further, certain chemical groups named herein are preceded by ashorthand notation indicating the total number of carbon atoms that areto be found in the indicated chemical group. For example; C₁-C₄alkyldescribes an alkyl group, as defined below, having a total of 1 to 4carbon atoms, and C₄-C₁₂cycloalkylalkyl describes a cycloalkylalkylgroup, as defined below, having a total of 4 to 12 carbon atoms. Thetotal number of carbons in the shorthand notation does not includecarbons that may exist in substituents of the group described.

As used in the specification and appended claims, unless specified tothe contrary, the following terms have the meaning indicated.

“C₁-C₆alkyl” refers to an alkyl radical as defined below containing oneto six carbon atoms. The C₁-C₆alkyl radical may be optionallysubstituted as defined below for an alkyl group. “C₁-C₄alkyl” refers toan alkyl radical as defined below containing one to four carbon atoms.The C₁-C₄alkyl radical may be optionally substituted as defined belowfor an alkyl group. “Alkyl” refers to a straight or branched hydrocarbonchain radical consisting solely of carbon and hydrogen atoms, containingno unsaturation, having from one to twelve carbon atoms, one to eightcarbon atoms, or one to six carbon atoms, or one to four carbon atoms,and which is attached to the rest of the molecule by a single bond,e.g., methyl, ethyl, n-propyl, 1-methylethyl (iso-propyl), n-butyl,n-pentyl, n-hexyl, and the like. Saturated branched alkyls includeisopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, 3-methylhexyl,2-methylhexyl, and the like. Representative saturated cyclic alkylsinclude cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,—CH₂-cyclopropyl, —CH₂— cyclobutyl, —CH₂-cyclopentyl, —CH₂-cyclohexyl,and the like.

“Alkenyl” refers to a straight or branched hydrocarbon chain radicalgroup consisting solely of carbon and hydrogen atoms, containing atleast one double bond, having from two to twelve carbon atoms,preferably two to eight carbon atoms and which is attached to the restof the molecule by a single bond. Representative straight chain andbranched alkenyls include ethylenyl, propylenyl, 1-butenyl, 2-butenyl,isobutylenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl,2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, and the like; whilerepresentative straight chain and branched alkynyls include acetylenyl,propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl, 3-methyl-1butynyl, and the like.

Unsaturated cyclic alkyls include cyclopentenyl and cyclohexenyl, andthe like. Cyclic alkyls, also referred to as “homocyclic rings,” includedi- and poly-homocyclic rings such as decalin and adamantyl. Unsaturatedalkyls contain at least one double or triple bond between adjacentcarbon atoms (referred to as an “alkenyl” or “alkynyl,” respectively).

“C₁₋₆alkanediyl” means a divalent C₁₋₆alkyl from which two hydrogenatoms are taken from the same carbon atom or from different carbonatoms, such as —CH₂—, —CH₂CH₂—, —CH(CH₃)—CH₂CH₂CH₂—, —CH(CH₃)CH₂CH₂—,—CHCH(CH₃)₂—, —CH₂C(CH₃)₂CH₂—, and the like.

“Heteroaryl” means an aromatic heterocycle ring of 5- to 10-members andhaving at least one heteroatom selected from nitrogen, oxygen andsulfur, and wherein the nitrogen and sulfur heteroatoms may beoptionally oxidized, and containing at least 1 carbon atom, includingboth mono- and bicyclic ring systems. Representative heteroaryls include(but are not limited to) furyl, benzofuranyl, thiophenyl,benzothiophenyl, pyrrolyl, indolyl, isoindolyl, azaindolyl, pyridyl,quinolinyl, isoquinolinyl, oxazolyl, isooxazolyl, oxadiazolyl,thiadiazolyl, benzoxazolyl, pyrazolyl, imidazolyl, benzimidazolyl,thiazolyl, benzothiazolyl, isothiazolyl, pyridazinyl, pyrimidinyl,pyrazinyl, triazinyl, cinnolinyl, phthalazinyl, and quinazolinyl.

“Heterocycle” (also referred to herein as a “heterocycle ring”) means a5- to 7-membered monocyclic, or 7- to 14-membered polycyclic,heterocycle ring which is either saturated (non-aromatic), unsaturatedor aromatic, and which contains from 1 to 4 heteroatoms independentlyselected from nitrogen, oxygen and sulfur, and wherein the nitrogen andsulfur heteroatoms may be optionally oxidized, and the nitrogenheteroatom may be optionally quaternized, including bicyclic rings inwhich any of the above heterocycles are fused to a benzene ring or atricyclic (and higher) heterocyclic ring. The heterocycle may beattached via any heteroatom or carbon atom. Heterocycles includeheteroaryls as defined above. Thus, in addition to the aromaticheteroaryls listed above, heterocycles also include (but are not limitedto) morpholinyl, pyrrolidinonyl, pyrrolidinyl, piperizinyl, piperidinyl,hydantoinyl, valerolactamyl, oxiranyl, oxetanyl, tetrahydrofuranyl,tetrahydropyranyl, tetrahydropyridinyl, tetrahydropyrimidinyl,tetrahydrothiophenyl, tetrahydrothiopyranyl, tetrahydropyrimidinyl,tetrahydrothiophenyl, tetrahydrothiopyranyl, oxopyrrolidinyl,imidazolidinone and the like.

Unless stated otherwise specifically in the specification, each of analkyl group, an alkenyl group, cyclic alkyl, C₁₋₆alkanediyl, andheterocycle may be optionally substituted by one of the followinggroups: alkyl, alkenyl, halo, haloalkenyl, cyano, nitro, aryl,cycloalkyl, heterocyclyl, heteroaryl, oxo, trimethylsilanyl, —OR⁴⁰,—OC(O)—R⁴⁰, —N(R⁴⁰)₂, —C(O)R⁴⁰, —C(O)OR⁴⁰, —C(O)N(R⁴⁰)₂, —N(R⁴⁰)C(O)OR⁴², —N(R⁴⁰)C(O)R⁴², —N(R⁴⁰)S(O)_(t)R⁴² (where t is 1 to 2),—S(O)_(t)OR⁴² (where t is 1 to 2), —S(O)_(p)R⁴² (where p is 0 to 2), and—S(O)_(t)N(R⁴⁰)₂ (where t is 1 to 2) where each R⁴⁰ is independentlyhydrogen, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl,heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl; and eachR⁴² is alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl,heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl.

“Haloalkyl” means an alkyl group having at least one hydrogen atomreplaced with a halogen, such as trifluoromethyl and the like.

“Halogen” means fluoro, chloro, bromo or iodo, typically fluoro orchloro.

“Hydroxy” means —OH.

“Alkoxy” means an alkyl moiety attached through an oxygen bridge (i.e.,—O-alkyl) and includes groups such as methoxy and ethoxy.

The compounds described herein may generally be utilized as the freeacid or free base. Alternatively, the compounds may be used in the formof acid or base addition salts. Acid addition salts of the free aminocompounds described herein may be prepared by methods well known in theart, and may be formed from organic and inorganic acids which formnon-toxic salts. Suitable organic acids include maleic, fumaric,benzoic, ascorbic, succinic, methanesulfonic, acetic, trifluoroacetic,oxalic, propionic, tartaric, salicylic, citric, gluconic, lactic,mandelic, cinnamic, aspartic, stearic, palmitic, glycolic, glutamic, andbenzenesulfonic acids. Suitable inorganic acids include hydrochloric,hydrobromic, sulfuric, phosphoric, and nitric acids. Base addition saltsincluded those salts that form with the carboxylate anion and includesalts formed with organic and inorganic cations such as those chosenfrom the alkali and alkaline earth metals (for example, lithium, sodium,potassium, magnesium, barium and calcium), as well as the ammonium ionand substituted derivatives thereof (for example, dibenzylammonium,benzylammonium, 2-hydroxyethylammonium, and the like). Thus, the term“pharmaceutically acceptable salt” of formula (I) is intended toencompass any and all acceptable salt forms.

With regard to stereoisomers, the compounds described herein may haveone or more chiral (or asymmetric) centers and may thus give rise toenantiomers, diastereomers, and other stereoisomeric forms that may bedefined, in terms of absolute stereochemistry, as (R)- or (S)-. When thecompounds described herein contain olefinic double bonds or othercenters of geometric asymmetry, and unless specified otherwise, it isintended that the compounds include both E and Z geometric isomers(e.g., cis or trans). Likewise, unless otherwise noted, all possibleisomers, as well as their racemic and optically pure forms, and alltautomeric forms are also intended to be included. It is thereforecontemplated that various stereoisomers and mixtures thereof include“enantiomers,” which refers to two stereoisomers whose molecules arenonsuperimposeable mirror images of one another. Thus, the compounds mayoccur in any isomeric form, including racemates, racemic mixtures, andas individual enantiomers or diastereomers.

“Prodrug” is meant to indicate a compound that may be converted underphysiological conditions or by solvolysis to a biologically activecompound described herein. Thus, the term “prodrug” refers to ametabolic precursor of a compound described herein that ispharmaceutically acceptable. A prodrug may be inactive when administeredto a subject in need thereof, but is converted in vivo to an activecompound as described herein. Prodrugs are typically rapidly transformedin vivo to yield the parent compound described herein, for example, byhydrolysis in blood. The prodrug compound often offers advantages ofsolubility, tissue compatibility or delayed release in a mammalianorganism (see, e.g., Bundgard, H., Design of Prodrugs (1985), pp. 7-9,21-24 (Elsevier, Amsterdam). A discussion of prodrugs is provided inHiguchi, T., et al., “Pro-drugs as Novel Delivery Systems,” A.C.S.Symposium Series, Vol. 14, and in Bioreversible Carriers in Drug Design,ed. Edward B. Roche, American Pharmaceutical Association and PergamonPress, 1987, both of which are incorporated in full by reference herein.

The term “prodrug” is also meant to include any covalently bondedcarriers which release the active compound as described herein in vivowhen such prodrug is administered to a mammalian subject. Prodrugs of acompound described herein may be prepared by modifying functional groupspresent in the compound described herein in such a way that themodifications are cleaved, either in routine manipulation or in vivo, tothe parent compound described herein. Prodrugs include compoundsdescribed herein wherein a hydroxy, amino or mercapto group is bonded toany group that, when the prodrug of the compound is administered to amammalian subject, cleaves to form a free hydroxy, free amino or freemercapto group, respectively. Examples of prodrugs include, but are notlimited to, ester and amide derivatives of hydroxy, carboxy, mercapto oramino functional groups in the compounds described herein and the like.

The compounds described herein may exist in a continuum of solid statesranging from fully amorphous to fully crystalline. Furthermore, some ofthe crystalline forms of the compounds of structures (A) or (B) mayexist as polymorphs. In addition, some of the compounds of structure (A)or (B) may also form solvates with water or other organic solvents. Theterm solvate is used herein to describe a molecular complex comprising acompound described herein and one or more pharmaceutically acceptablesolvent molecules. Such solvates are similarly included within the scopeof this disclosure.

In certain embodiments, the compounds described include allpharmaceutically acceptable isotopically labeled compounds of structures(A) or (B) where on or more atoms are replaced by atoms having the sameatomic number but a different atomic mass. Examples include ²H(deuterium) and ³H (tritium) for hydrogen, ¹¹C, ¹³C and ¹⁴C for carbon,³⁶Cl for chlorine, ¹⁸F for fluorine, ¹²³I and ¹²⁵I for iodine, ¹³N and¹⁵N for nitrogen, and ³⁵S for sulfur.

As one of skill in the art would appreciate, any of the aforementionedcompounds may incorporate radioactive isotopes. Accordingly, alsocontemplated is use of isotopically-labeled compounds identical to thosedescribed herein, wherein one or more atoms are replaced by an atomhaving an atomic mass or mass number different from the atomic mass ormass number usually found in nature. Examples of isotopes that can beincorporated into these compounds include isotopes of hydrogen, carbon,nitrogen, oxygen, phosphorous, fluorine and chlorine, such as, but notlimited to, ²H, ³H, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S, ¹⁸F and³⁶Cl, respectively. Certain isotopically-labeled compounds, for examplethose into which radioactive isotopes such as ³H and ¹⁴C areincorporated, are also useful in drug or substrate tissue distributionassays. Tritiated hydrogen (³H) and carbon-14 (¹⁴C) isotopes areparticularly preferred for their ease of preparation and detectability.Substitution with heavier isotopes such as deuterium (²H) can providecertain therapeutic advantages resulting from greater metabolicstability, for example increased in vivo half-life or reduced doserequirements and, therefore, may be preferred in some circumstances.Isotopically-labeled compounds can generally be prepared by performingprocedures routinely practiced in the art.

Compound Synthesis

The compounds described herein may be prepared by known organicsynthesis techniques, including the methods described in more detail inthe Examples. In general, the compounds of structures (A) and (B) abovemay be made by the following reaction schemes, wherein all substituentsare as defined above unless indicated otherwise.

Benzyl halides of the formula (I), where X is a halide, can be reactedwith sodium azide in a solvent such as acetonitrile, ethanol or DMF,optionally in the presence of sodium iodide, potassium iodide orn-tetrabutylammonium iodide, at a temperature from room temperature tothe boiling point of the solvent to yield azide of formula (II). Azidesof formula (II) can be reacted with ethyl propiolate in a solvent suchas ethanol at a temperature from room temperature to 90° C. to yieldtriazoles of formula (III).

Alternatively, triazoles of formula (III) can be treated with a basesuch as lithium hydroxide or potassium hydroxide, in a solvent mixturesuch as methanol and H₂O or dioxane and H₂O, at a temperature from roomtemperature to the boiling point of the solvent mixture to yield acidsof formula (V).

Triazoles of formula (III) can be reacted with hydrazine hydrate inethanol at a temperature from room temperature to 80° C. to givehydrazides of formula (VII).

Alternatively, triazoles of formula (III) can be treated with a basesuch as lithium hydroxide or potassium hydroxide, in a solvent mixturesuch as methanol and H₂O, or dioxane and H₂O, at a temperature from roomtemperature to the boiling point of the solvent mixture to yield acidsof formula (V).

Hydrazides of formula (VII) can be reacted with sodium nitrite inaqueous hydrochloric acid at a temperature from 0° C. to roomtemperature to yield azides of formula (VIII). The resulting azides offormula (VIII) can be reacted in ethanol at 85° C. to give compounds offormula (IX).

Alternatively, azides of formula (VIII) can be reacted with alcohols offormula HO—R₄ in the presence of a solvent such as tetrahydrofuran,dioxane or DMF, at a temperature from room temperature to the boilingpoint of the solvent to give carbamates of the formula (XIV).

Amino triazoles of formula (X) are produced by treating compounds offormula (IX) with a base such as sodium hydroxide, lithium hydroxide orpotassium hydroxide in ethanol and water at a temperature from roomtemperature to 85° C.

Amino triazoles of formula (X) can be treated with acids of formulaHOOC—R⁵ using standard coupling conditions using a coupling agent suchas HATU in the presence of a base such as N,N-diisopropylethylamine ortriethylamine, in a solvent such as dichloromethane or DMF at roomtemperature to yield compounds of formula (XI). Other suitable couplingconditions include N,N-Dicyclohexylcarbodiimide or1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide in the presence of4-Dimethylaminopyridine and a solvent such as dichloromethane at roomtemperature. Alternatively, amino triazoles of formula (X) can betreated with acid chlorides of formula ClOC—R⁵ in the presence of a basesuch as triethylamine, pyridine or N,N-diisopropylethylamine, in asolvent such as dichloromethane, tetrahydrofuran or dioxane, at atemperature from room temperature to the boiling point of the solvent togive compounds of formula (XI).

Ureas of formula (XII) can be obtained by first reacting amino triazolesof formula (X) with a base such as pyridine, triethylamine orN,N-diisopropylethylamine and triphosgene or phosgene, in a solvent suchas dichloromethane at a temperature of 0° C. to room temperature.Subsequently, amines of the formula H₂N—R₅ are added at roomtemperature.

Also, acids of formula (V) can be reacted with diphenylphosphoryl azidein the presence of a base such as triethylamine orN,N-diisopropylethylamine, in a solvent such as tert-butanol at atemperature from room temperature to 90° C. to give isocyanates offormula (XIII) which can yield compound (IX) upon treatment with ethanolor compound (XII) upon treatment with an appropriate amine.

Compounds of formula (XVI) where R₁ and R₂ are taken together to form aheterocycle may be obtained from amines of formula (X) by alkylationwith an appropriate bis-electrophile (such as a dihalide, dimesylate,ditosylate, and the like) and an appropriate base such as DIEA orpotassium carbonate. Formula (X) and an aldehyde may undergo a reductiveamination to yield (XV) where R₁═R₂. Alternatively, compound (XV) whereR₁ may be the same or different than R₂ may be synthesized via reductiveamination of a compound of formula (XVII) and an appropriate aldehyde. Acompound of formula (XVII) may be synthesized by boron hydride reductionof compound (XI). In general, the compounds used in the reactionsdescribed herein may be made according to organic synthesis techniquesknown to those skilled in this art, starting from commercially availablechemicals and/or from compounds described in the chemical literature.“Commercially available chemicals” may be obtained from standardcommercial sources including Acros Organics (Pittsburgh Pa.), AldrichChemical (Milwaukee Wis., including Sigma Chemical and Fluka), ApinChemicals Ltd. (Milton Park UK), Avocado Research (Lancashire U.K.), BDHInc. (Toronto, Canada), Bionet (Cornwall, U.K.), Chemservice Inc. (WestChester Pa.), Crescent Chemical Co. (Hauppauge N.Y.), Eastman OrganicChemicals, Eastman Kodak Company (Rochester N.Y.), Fisher Scientific Co.(Pittsburgh Pa.), Fisons Chemicals (Leicestershire UK), FrontierScientific (Logan Utah), ICN Biomedicals, Inc. (Costa Mesa Calif.), KeyOrganics (Cornwall U.K.), Lancaster Synthesis (Windham N.H.), MaybridgeChemical Co. Ltd. (Cornwall U.K.), Parish Chemical Co. (Orem Utah),Pfaltz & Bauer, Inc. (Waterbury Conn.), Polyorganix (Houston Tex.),Pierce Chemical Co. (Rockford Ill.), Riedel de Haen AG (Hanover,Germany), Spectrum Quality Product, Inc. (New Brunswick, N.J.), TCIAmerica (Portland Oreg.), Trans World Chemicals, Inc. (Rockville Md.),and Wako Chemicals USA, Inc. (Richmond Va.).

Methods known to one of ordinary skill in the art may be identifiedthrough various reference books and databases. Suitable reference booksand treatise that detail the synthesis of reactants useful in thepreparation of compounds of the present disclosure, or providereferences to articles that describe the preparation, include forexample, “Synthetic Organic Chemistry,” John Wiley & Sons, Inc., NewYork; S. R. Sandler et al., “Organic Functional Group Preparations,” 2ndEd., Academic Press, New York, 1983; H. O. House, “Modern SyntheticReactions”, 2nd Ed., W. A. Benjamin, Inc. Menlo Park, Calif. 1972; T. L.Gilchrist, “Heterocyclic Chemistry”, 2nd Ed., John Wiley & Sons, NewYork, 1992; J. March, “Advanced Organic Chemistry: Reactions, Mechanismsand Structure,” 4th Ed., Wiley-Interscience, New York, 1992. Additionalsuitable reference books and treatise that detail the synthesis ofreactants useful in the preparation of compounds of the presentdisclosure, or provide references to articles that describe thepreparation, include for example, Fuhrhop, J. and Penzlin G. “OrganicSynthesis: Concepts, Methods, Starting Materials”, Second, Revised andEnlarged Edition (1994) John Wiley & Sons ISBN: 3-527-29074-5; Hoffman,R. V. “Organic Chemistry, An Intermediate Text” (1996) Oxford UniversityPress, ISBN 0-19-509618-5; Larock, R. C. “Comprehensive OrganicTransformations: A Guide to Functional Group Preparations” 2nd Edition(1999) Wiley-VCH, ISBN: 0-471-19031-4; March, J. “Advanced OrganicChemistry: Reactions, Mechanisms, and Structure” 4th Edition (1992) JohnWiley & Sons, ISBN: 0-471-60180-2; Otera, J. (editor) “Modern CarbonylChemistry” (2000) Wiley-VCH, ISBN: 3-527-29871-1; Patai, S. “Patai's1992 Guide to the Chemistry of Functional Groups” (1992) InterscienceISBN: 0-471-93022-9; Quin, L. D. et al. “A Guide to OrganophosphorusChemistry” (2000) Wiley-Interscience, ISBN: 0-471-31824-8; Solomons, T.W. G. “Organic Chemistry” 7th Edition (2000) John Wiley & Sons, ISBN:0-471-19095-0; Stowell, J. C., “Intermediate Organic Chemistry” 2ndEdition (1993) Wiley-Interscience, ISBN: 0-471-57456-2; “IndustrialOrganic Chemicals: Starting Materials and Intermediates: An Ullmann'sEncyclopedia” (1999) John Wiley & Sons, ISBN: 3-527-29645-X, in 8volumes; “Organic Reactions” (1942-2000) John Wiley & Sons, in over 55volumes; and “Chemistry of Functional Groups” John Wiley & Sons, in 73volumes.

Specific and analogous reactants may also be identified through theindices of known chemicals prepared by the Chemical Abstract Service ofthe American Chemical Society, which are available in most public anduniversity libraries, as well as through on-line databases (the AmericanChemical Society, Washington, D.C., may be contacted for more details).Chemicals that are known but not commercially available in catalogs maybe prepared by custom chemical synthesis houses, where many of thestandard chemical supply houses (e.g., those listed above) providecustom synthesis services. A reference for the preparation and selectionof pharmaceutical salts of the present disclosure is P. H. Stahl & C. G.Wermuth “Handbook of Pharmaceutical Salts,” Verlag Helvetica ChimicaActa, Zurich, 2002.

Methods for Characterizing and Identifying Compounds

Effectiveness of a compound as a treatment for neurological disordersmay be determined by various assay techniques. The AnticonvulsantScreening Program (ASP) of the National Institute of NeurologicalDiseases and Stroke facilitates the development of new anticonvulsantdrugs by providing screening and other services used to evaluate novelcandidates in highly predictive and standardized assays. Many of thecompounds described herein were tested in one or more assays of the ASP.

The standard models incorporated into anticonvulsant screening includethe maximal electroshock test (MES), the subcutaneous Metrazol test(scMET), and evaluations of toxicity (minimal motor impairment, MMI).Additional models include the following: seizures induced by otherchemoconvulsants; minimal clonic seizures in mice (6 Hz test);hippocampal-kindled rats; the in vitro spontaneous bursting model ofpharmacoresistance in kainate-treated rats; lamotrigine-resistantamygdala-kindled rats; focal seizures in corneal-kindled mice;pilocarpine-induced status epilepticus in rats; and Frings audiogenicseizure susceptible mice.

Maximal Electroshock Test (MES)

The MES is a model for generalized tonic-clonic seizures and provides anindication of a compound's ability to prevent seizure spread when allneuronal circuits in the brain are maximally active. These seizures arehighly reproducible and are electrophysiologically consistent with humanseizures.

Subcutaneous Metrazol Seizure Threshold Test (scMET)

Excitatory and inhibitory neurotransmission plays a critical role inmediating normal neuronal signaling, and an imbalance between these twopathways can contribute to the onset of seizures, and ultimatelyepileptogenesis. Chemically disrupting this finely tuned balance canartificially induce a seizure. Subcutaneous injection of the convulsantmetrazol produces clonic seizures in laboratory animals. The scMET testdetects the ability of a test compound to raise the seizure threshold ofan animal and thus protect it from exhibiting a clonic seizure.

Acute Toxicity—Minimal Motor Impairment (MMI)

To assess a compound's undesirable side effects (toxicity), animals aremonitored for overt signs of impaired neurological or muscular function.In mice, the rotorod procedure is used to disclose minimal muscular orneurological impairment. When a mouse is placed on a rod that rotates ata speed of 6 rpm, the animal can maintain its equilibrium for longperiods of time. The animal is considered to be exhibiting motorimpairment if it falls off this rotating rod three times during a 1-minperiod. In rats, minimal motor deficit is indicated by ataxia, which ismanifested by an abnormal, uncoordinated gait. Rats used for evaluatingtoxicity are examined before the test drug is administered sinceindividual animals may have peculiarities in gait, equilibrium, placingresponse, etc., which might be attributed erroneously to the testsubstance. In addition to MMI, animals may exhibit a circular or zigzaggait, abnormal body posture and spread of the legs, tremors,hyperactivity, lack of exploratory behavior, somnolence, stupor,catalepsy, loss of placing response, and changes in muscle tone.

Other Chemoconvulsant Tests

In addition to the intravenous scMET test, other chemoconvulsants can beemployed to test for anticonvulsant activity. The GABA_(A) antagonist,bicuculline, and the GABA_(A) chloride-channel blocker, picrotoxin, bothinduce seizures by disrupting normal inhibitory neurotransmission (i.e.,weakening synaptic inhibition) through blocking GABA_(A) receptorfunction. Both these drugs are used as an acute seizure model for rapidassessment of potential anticonvulsants.

Minimal Clonic Seizure Test

Some clinically useful AEDs are ineffective in the standard MES andscMET tests but still have anticonvulsant activities in vivo. In orderto identify potential AEDs with this profile, compounds may be tested inthe minimal clonic seizure (6 Hz or ‘psychomotor’) test. Like themaximal electroshock (MES) test, the minimal clonic seizure test is usedto assess a compound's efficacy against electrically-induced seizuresbut uses a lower frequency (6 Hz) and longer duration of stimulation (3s). Mice will display seizures characterized by a minimal clonic phasefollowed by stereotyped, automatistic behaviors described as beingsimilar to the aura of human patients with partial seizures. Animals notdisplaying this behavior are considered protected. This test may also beconducted at 22 and 44 mA, with 44 mA being more refractory totreatment.

The Hippocampal-Kindled Rat Model

The hippocampal-kindled rat provides an experimental model of focalseizures that become secondarily generalized. This rat model is usefulfor not only identifying compounds effective against partial seizures,but also allows for the investigation of brain networks that maycontribute to seizure spread and generalization from a focus. Moreover,this model provides a temporal framework for assessing drug efficacy ina focal seizure model. Specifically, the refractory period of individualanimals is sufficiently short to permit repeated stimulations over ashort time span. Second, this kindled rat model can be employed toassess the ability of an investigational compound to block fully kindledseizures evoked by an electrical stimulus. Finally, the hippocampalkindled rat model can also be used to assess the ability of aninvestigational compound to elevate threshold to focal firing.

The In Vitro Spontaneous Bursting Model of Pharmacoresistance

The medial entorhinal cortex-hippocampal (mEC-HC) slice obtained fromkainic acid (KA)-treated animals is an in vitro screen meant to identifycompounds that may be effective in pharmacoresistant epilepsy. KAtreatment is an accepted animal model of temporal lobe epilepsy (TLE),with an initial insult resulting in status epilepticus, followed by asustained latent period that subsequently gives way to the developmentof spontaneous seizures. The mEC-HC slices collected from KA-treatedrats exhibit spontaneous electrographic “interictal-like” events thatare pharmacoresistant to traditional AEDs. Moreover, the mEC-HC slicesobtained from KA-treated rats are hyperexcitable in normal artificialcerebrospinal fluid (ACSF) solution as early as one week followingKA-induced SE. This hyperexcitability of slices from KA-treated ratssignificantly decreases the time it takes for spontaneous burst (SB)discharges to be elicited when compared to the low-Mg²⁺ mEC-HC sliceobtained from control rats.

Lamotrigine-(LTG) Resistant Amygdala Kindled Rat Model

The addition of LTG during the development of seizures ultimatelyimpairs the effectiveness of LTG against a fully expressed kindledseizure. Thus, the addition of low doses of LTG during the kindlingacquisition phase (through stimulation of an electrode implanted in theamygdala of a rat) produces a model capable of differentiating betweentraditional anticonvulsants and investigational drugs that are effectivein blocking the fully expressed kindled seizure, and may therefore beeffective in patients with intractable epilepsy.

Focal Seizures in Corneal-Kindled Mice

In this model, the optic nerve is used to deliver a trans-cornealelectrical stimulation to the brain in a non-invasive manner. Thecorneal kindled mouse demonstrates a pharmacological profile consistentwith the hippocampal-kindled rat model, and with human partial epilepsy.The nonsurgical nature of the procedure allows for rapid assessment ofinvestigational drugs for this condition,

Pilocarpine Induced Status Epilepticus

The pilocarpine model is a well characterized model of statusepilepticus (SE). This model shares many characteristics with nerveagent induced seizures since the seizures that result in both models arecholinergic mediated. Clinical manifestations following an acute dose ofpilocarpine include ataxia, akinesia and facial automatisms. Thesesymptoms quickly progress to full SE which can last up to twelve hours.This activity can be correlated closely with electrographic seizureactivity. Rats that survive the acute insult later display spontaneousrecurrent seizures and mossy fiber sprouting.

The Frings Audiogenic Seizure—(AGS) Susceptible Mouse Model

Frings AGS-susceptible mice are genetically susceptible to sound-inducedreflex seizures. It has a well-validated epilepsy phenotype and isparticularly useful as a screening model. Beginning at about 21 days ofage, Frings AGS-susceptible mice display prominent seizure activity inresponse to a high-intensity sound stimulus. They then remainsusceptible to sound throughout their life. Their seizure phenotype ischaracterized by wild running, loss of righting reflex, tonic flexion,and tonic extension in response to high-intensity sound stimulation. Incontrast to other seizure models, the Frings AGS-susceptible mouse isnon-discriminatory with respect to clinical categories of anticonvulsantdrugs. For this reason, this model is used to screen novelinvestigational compounds, and may also aid in the identification andcharacterization of compounds effective against inherited forms ofepilepsy.

Other tests for efficacy of novel compounds for neurological disordersinclude the soman-induced seizure model in rats, and theharmaline-induced tremor model in mice.

Soman-Induced Seizures

The organophosphate nerve agent soman induces seizures throughirreversible inactivation of the enzyme acetylcholinesterase, resultingin a large increase in cholinergic tone in the brain and peripheraltissues. Rats exposed to soman gas can be used as a model fororganophosphate poisoning. Rats exposed to soman rapidly enter aconvulsive state, where strong ictal activity can be recorded by EEG.Test compounds are injected intramuscularly or subcutaneously atdifferent times after the onset of seizures. Since human victims in anemergency mass casualty situation are unlikely to gain access totreatment for a long period after initial exposure, those compoundscapable of blocking seizure activity when administered at later timesafter seizure induction will likely be the most efficacious andpractical for use.

Harmaline-Induced Tremor

Essential tremor (ET) is the most common movement disorder in humans.While several mechanisms and genetic animal models have been proposedfor ET, administration of the β-carboline derivate harmaline to mice isconsidered the standard model for this disorder. Harmaline causesgeneralized tremors, with a frequency of 11-14 Hz, the same tremorfrequency as ET. Pretreatment with current anti-ET therapeutics such aspropranolol (β-blocker) and primidone (antiepileptic) attenuatesharmaline-induced tremors in mice.

Compounds described herein as shown in the Examples below (includingsome chemical intermediates) were generally tested in one or more of theassays shown. A person skilled in the art readily appreciates that invitro assays and methods and in vivo animal models are performed usingthe appropriate controls.

The compounds described herein have utility over a wide range oftherapeutic applications, and may be used to treat a variety ofneurological disorders in humans, both men and women, as well as mammalsin general (also referred to herein as a “subject”). For example, thecompounds of structures (A) and (B) (as well as the specific compoundsdisclosed herein) may be used to treat or prevent neurological disordersand diseases, especially essential tremor, epilepsy, status epilepticus,and nerve agent exposure. Such compounds may be used in combination withother anticonvulsant agents, and/or in combination with deep brainstimulation (DBS).

As understood by a person skilled in the medical art, the terms, “treat”and “treatment,” refer to medical management of a disease, disorder, orcondition of a subject (i.e., patient, individual) (see, e.g., Stedman'sMedical Dictionary). In general, an appropriate dose (i.e., effectiveamount, therapeutic amount) and treatment regimen provide the compoundin an amount sufficient to provide therapeutic and/or prophylacticbenefit. Therapeutic benefit for subjects to whom the compound(s)described herein are administered, includes, for example, an improvedclinical outcome, wherein the object is to prevent or slow or retard(lessen) an undesired physiological change associated with the disease,or to prevent or slow or retard (lessen) the expansion or severity ofsuch disease. As discussed herein, effectiveness of the one or morecompounds may include beneficial or desired clinical results thatcomprise, but are not limited to, abatement, lessening, or alleviationof symptoms that result from or are associated with the disease to betreated; decreased occurrence of symptoms; improved quality of life;longer disease-free status (i.e., decreasing the likelihood or thepropensity that a subject will present symptoms on the basis of which adiagnosis of a disease is made); diminishment of extent of disease;stabilized (i.e., not worsening) state of disease; delay or slowing ofdisease progression; amelioration or palliation of the disease state;and remission (whether partial or total), whether detectable orundetectable; and/or overall survival.

“Treatment” can also mean prolonging survival when compared to expectedsurvival if a subject were not receiving treatment. Subjects in need oftreatment include those who already have the disease or disorder as wellas subjects prone to have or at risk of developing the disease ordisorder, and those in which the disease, condition, or disorder is tobe prevented (i.e., decreasing the likelihood of occurrence orrecurrence of the disease or disorder).

A subject (i.e., patient, individual) in need of treatment with acompound as described herein may be a human or may be a non-humanprimate or other animal (i.e., veterinary use) who has developedsymptoms of neuronal dysfunction and control including tremor andseizures or who is at risk for developing a neurological disease ordisorder, and more specifically symptoms of neuronal dysfunction andcontrol including tremors or seizures. Non-human animals that may betreated include mammals, for example, non-human primates (e.g., monkey,chimpanzee, gorilla, and the like), rodents (e.g., rats, mice, gerbils,hamsters), lagomorphs, swine (e.g., pig, miniature pig), equine, canine,feline, bovine, elephants, bears and other domestic, farm, and zooanimals.

Pharmaceutical Compositions

The present disclosure further provides for pharmaceutical compositionscomprising any one of the compounds described herein (a compound ofstructures (A) and (B), including the specific compounds describedherein) and a pharmaceutically acceptable excipient for use in themethods for treating neurological disorders and diseases, especiallyessential tremor, epilepsy, status epilepticus, and nerve agentexposure. A pharmaceutically acceptable excipient is a physiologicallyand pharmaceutically suitable non-toxic and inactive material oringredient that does not interfere with the activity of the activeingredient; an excipient also may be called a carrier.

For the purposes of administration to a subject, the compounds describedherein may be formulated as pharmaceutical compositions that comprise acompound and a pharmaceutically acceptable excipient (carrier and/ordiluent). The compound is present in the composition in an amount whichis effective to treat a particular disorder and preferably withacceptable toxicity to the patient. Appropriate concentrations anddosages can be readily determined by one skilled in the art.

Pharmaceutically acceptable excipients, carriers and diluents arefamiliar to those skilled in the art. For compositions formulated asliquid solutions, acceptable carriers and/or diluents include saline andsterile water, and may optionally include antioxidants, buffers,bacteriostats and other common additives. The compositions can also beformulated as pills, capsules, granules, or tablets which contain, inaddition to the compound, diluents, dispersing and surface activeagents, binders, and lubricants. One skilled in this art may furtherformulate the compound in an appropriate manner, and in accordance withaccepted practices. Pharmaceutically acceptable excipients are wellknown in the pharmaceutical art and described, for example, in Rowe etal., Handbook of Pharmaceutical Excipients: A Comprehensive Guide toUses, Properties, and Safety, 5^(th) Ed., 2006, and in Remington: TheScience and Practice of Pharmacy (Gennaro, 21^(st) Ed. Mack Pub. Co.,Easton, Pa. (2005)). Examples of pharmaceutically acceptable excipientsinclude sterile saline and phosphate buffered saline at physiologicalpH. Preservatives, stabilizers, dyes, buffers, and the like may beprovided in the pharmaceutical composition. In addition, antioxidantsand suspending agents may also be used.

The compounds and pharmaceutical compositions comprising the compoundsmay be delivered to a subject by any one of several administrationmethods routinely practiced in the art, including systemicadministration. As used herein, systemic administration includes oraland parenteral methods of administration.

For oral administration, suitable pharmaceutical compositions includepowders, granules, pills, tablets, lozenges, chews, gels, and capsulesas well as liquids, syrups, suspensions, elixirs, and emulsions. Thecompounds described herein may also be used in fast dissolving, fastdisintegrating dosage forms. These compositions may also includeanti-oxidants, flavorants, preservatives, suspending, thickening andemulsifying agents, colorants, flavoring agents and otherpharmaceutically acceptable additives. Formulations for oraladministration may be formulated to be immediate release or modifiedrelease, where modified release includes delayed, sustained, pulsed,controlled, targeted and programmed release.

For parenteral administration, the compounds described herein areadministered directly into the blood stream, into muscle, or into aninternal organ via an intravenous, intraarterial, intraperitoneal,intramusuclar, subcutaneous or other injection or infusion. Parenteralformulations may be prepared in aqueous injection solutions which maycontain, in addition to the compound, buffers, antioxidants,bacteriostats, salts, carbohydrates, and other additives commonlyemployed in such solutions. Parenteral administrations may be immediaterelease or modified release (such as an injected or implanted depot).

Compounds and pharmaceutical compositions of same described herein mayalso be administered topically, (intra)dermally, or transdermally to theskin or mucosa. Typical formulations include gels, hydrogels, lotions,solutions, creams, ointments, dressings, foams, skin patches, wafers,implants and microemulsions. The compounds may also be administered viainhalation or intanasal administration, such as with a dry powder, anaerosol spray or as drops. Additional routes of administration for thecompounds described herein include intravaginal and rectal (by means ofa suppository, pessary or enema), and ocular, and aural.

The following examples are provided for purposes of illustration, notlimitation. In summary, compounds may be assayed by the general methodsdisclosed in Examples 17-29. The following Examples 1-16 disclose thesynthesis of representative compounds of structures (A) and (B).

EXAMPLES HPLC Methods for Analyzing the Samples (Retention Time, t_(R),in Minutes)

Method 1: Platform: Agilent 1100 series, equipped with an auto-sampler,an UV detector (220 nm and 254 nm), a MS detector (APCI); HPLC column:Phenomenex Synergi-Max-RP 2.0×50 mm; HPLC gradient: 1.0 mL/min., from 5%acetonitrile in water to 95% acetonitrile in water in 13.5 min.,maintaining 95% for 2 min. Both acetonitrile and water have 0.025% TFA.

Method 2: Platform: Dionex, equipped with an auto-sampler, an UVdetector (220 nm and 254 nm), a MS detector (APCI); HPLC column:Waters)(Bridge C18, 3.0×100 mm; HPLC gradient: 1.4 mL/min., from 5%acetonitrile in water to 99% acetonitrile in water in 7.8 min.,maintaining 99% for 1.6 min. Both acetonitrile and water have 0.04%NH₄OH.

Method 3: Platform: Agilent, equipped with an auto-sampler, an UVdetector (220 nm and 254 nm), a MS detector (APCI); HPLC column: WatersXTerraMS C18, 3.0×250 mm; HPLC gradient: 1.0 mL/min., from 10%acetonitrile in water to 90% acetonitrile in water in 46 min.maintaining 90% for 7.0 min. Both acetonitrile and water have 0.025%TFA.

Method 4: Platform: Agilent 1100 series, equipped with an auto-sampler,an UV detector (220 nM and 254 nM), a MS detector (APCI); HPLC column:Phenomenex Synergi: MAX-RP, 2.0×50 mm column; HPLC gradient: 1.0mL/minute, from 10% acetonitrile in water to 90% acetonitrile in waterin 2.5 minutes, maintaining 90% for 1 minute. Both acetonitrile andwater have 0.025% TFA.

Example 1 1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-amine

Step 1A: 2,6-Difluorobenzylazide

A mixture of 2,6-difluorobenzyl bromide (4.0 g, 19.3 mmol), sodiumiodide (2.9 g, 19.3 mmol) and sodium azide (3.8 g, 57.9 mmol) inacetonitrile (20 mL) was stirred at 70° C. for 12 hours. The solutionwas diluted with saturated sodium bicarbonate solution and the mixturewas extracted with ethyl acetate (3×100 mL). The combined organicextracts were dried (Na₂SO₄), and the solvent removed under reducedpressure to yield 2,6-difluorobenzylazide 1a as a light brown oil (65%).

Step 1B: 1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazole-4-carboxylic acidethyl ester

To a solution of 1a (2.2 g, 13.0 mmol) in ethanol (10.0 mL) was addedethyl propiolate (1.40 g, 14.3 mmol). The reaction mixture was stirredat 80° C. for 5 hours. Upon cooling the product crystallized out. Theproduct crystals were filtered and washed with ethanol.Recrystallization from hot methanol yielded1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazole-4-carboxylic acid ethyl ester1b as off white crystals (45%). LCMS (APCI) m/z 268.0 (MH⁺). ¹H NMR (300MHz, DMSO-d₆): δ 8.85 (s, 1H), 7.47-7.57 (m, 1H), 7.14-7.22 (m, 2H),5.74 (bs, 2H), 4.29 (q, J=7.5 Hz, 2H), 1.28 (t, J=7.5 Hz, 3H).

Step 1C: 1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazole-4-carboxylic acid

To 1b (2.0 g, 7.5 mmol) stirring in a 1:1 solution of methanol (5.0 mL)and H₂O (5.0 mL) was added lithium hydroxide (0.888 g, 37 mmol). Thereaction mixture was heated to 50° C. for 2 hours. Upon cooling, thesolution was acidified with aqueous 1 N HCl to a pH of −3.0. Theprecipitate was filtered and washed with H₂O (30 mL) and dried in avacuum oven to yield1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazole-4-carboxylic acid 1c as anoff white solid (85%). LCMS (Method 4) m/z 239.7 [MH⁺], t_(R)=1.99 min.

Step 1D 1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazole-4-carbonylchloride

To 1c (20 g) was added thionyl chloride (60 mL) and the mixture refluxedfor 1 h. The solution was concentrated and dried under vacuum to givethe acid chloride 1d as a white solid.

Step 1E 1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazole-4-carbonylazide

Acid chloride 1d was dissolved in acetone (120 mL) and a mixture ofsodium azide (8.2 g) in water (100 mL) was added slowly keeping theinternal temperature below 10° C. The mixture was left to warm to r.t.overnight. The product was filtered off as a solid washing with waterand was dried in a vacuum desiccator over NaOH pellets overnight to givethe azide 1e as a white solid (21.6 g).

Step 1F 1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-amine

Azide 1e was refluxed in dry ethanol (100 mL) overnight. NaOH (4 Maqueous, 20 mL) was added carefully and reflux continued overnight. Themixture was cooled to r.t. and HCl (12 N) was slowly added to acidify topH 1. The ethanol was removed in vacuo and water and DCM were added. Theproduct extracted in to the aqueous layer which was washed with DCM andthe organic extracts discarded. The aqueous phase was brought to pH 10by slow addition of NaOH (12 M, aqueous) and the product precipitatedwith stirring. After 30 minutes stirring the product was filtered offwashing with water several times to give the amine product if as anoff-white solid (12.3 g). Chromatography on silica gel eluting withethyl acetate/hexane gave a purer sample for testing. LCMS (Method 4)m/z 211.1 [MH⁺], t_(R)=1.46 min.

Example 2 1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-amine

Step 2A: 1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazole-4-carboxylic acidhydrazide

To 1b (1.6 g, 6.0 mmol) was added hydrazine hydrate (0.9 g, 18.0 mmol)and ethanol (5 mL). The reaction mixture was heated in a sealed vesseland heated at 80° C. for 1 hour. The mixture was diluted with H₂O (20mL) and filtered using H₂O to rinse the filter cake to yield1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazole-4-carboxylic acid 2a as anoff white solid which was used without additional purification in thenext step. LCMS (Method 4) m/z 254.1 [MH⁺], t_(R)=1.81 min.

Step 2B: 1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazole-4-carbonyl azide

A mixture of 2a (1.0 g, 3.9 mmol) and sodium nitrite (0.54 g, 7.8 mmol)was stirred in aqueous 2N HCl (5.0 mL) in an ice bath at 0° C. Themixture was allowed to warm to room temperature and stirred for 5 hours.The mixture was diluted with H₂O (50 mL) and filtered using cold H₂O torinse the filter cake to yield1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazole-4-carbonyl azide 1e as awhite solid (80% over two steps). LCMS (Method 4) m/z 265.1 [MH⁺],t_(R)=2.45 min.

Step 2C: [1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-carbamic acidethyl ester

Ethanol (5.0 mL) was added to 1e (1.37 g, 5.2 mmol) and the mixture wasstirred at 85° C. for 12 hrs. The mixture was concentrated under vacuumto yield [1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-carbamic acidethyl ester 2c (95% yield). LCMS (Method 4) m/z 283.0 [MH⁺], t_(R)=2.08min.

Step 2D: 1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-ylamine

To 2c (1.39 g, 4.9 mmol) was added a solution of 1:1 aqueous 2NNaOH/EtOH (5 mL of 2N NaOH, 5 mL of EtOH). The reaction mixture wasstirred in a sealed vessel at 85° C. for 1 hour. Upon cooling, thereaction mixture was neutralized to pH 7.5 using aqueous 1N HCl. Thesolution was diluted with brine and washed with 5% MeOH/DCM (3×50 mL).The combined organic extracts were dried (Na₂SO₄), and the solventremoved under reduced pressure to yield1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-ylamine if as an off-whitesolid (90%). LCMS (Method 1) m/z 211.0 [MH⁺], t_(R)=2.03 min. ¹H NMR(300 MHz, CDCl₃): δ 7.33 (m, 1H), 6.40 (m, 3H), 5.48 (s, 2H), 3.56 (s,2H).

Other compounds which were made following this procedure include:

1-(4-fluoro-benzyl)-1H-[1,2,3]triazol-4-ylamine, 2e, LCMS (Method 1) m/z192.8 [MH⁺], t_(R)=1.89 min.;

1-(4-trifluoromethyl-benzyl)-1H-[1,2,3]triazol-4-ylamine, 2f, LCMS(Method 4) m/z 243.1 [MH⁺], t_(R)=1.79 min.;

1-(3-fluoro-benzyl)-1H-[1,2,3]triazol-4-ylamine, 2g, LCMS (Method 4) m/z193.1 [MH⁺], t_(R)=1.48 min.; and

1-benzyl-1H-1,2,3-triazol-4-amine, 2h, LCMS (Method 4) m/z 175.1 [MH⁺],t_(R)=1.40 min.

Example 3 (2S)-2-Amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide

Step 3A:(2S)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide

Amino triazole if (1.4 g), Boc-L-Phe-OH (1.8 g) and DIEA (1.75 mL) werecombined in DCM (10 mL) and DIVIF (10 mL). HATU (3.6 g) was added slowlyover 10 minutes with stirring and then was stirred at r.t. overnight.EtOAc and DCM were added and the organic layer was washed with 0.5 MNaOH, 1 M acetic acid, and brine, dried over MgSO₄ and concentrated togive a solid. The solid was re-dissolved in hot DCM and ether was addedto crystallize product. The resulting solid was filtered, washed withether and dried by suction to give the Boc-amine product as an off-whitesolid (2.26 g). The solid was dissolved in DCM (20 mL) and HCl (4M indioxane, 20 mL) was added and stirred at r.t. for 2 h. Approx. 80% ofthe solvent was removed in vacuo and ether was added and stirredvigorously to slowly precipitate the product amine as the HCl salt. Thesolid was filtered off under a stream of N₂, washed with ether, dried bysuction under a stream of N₂ and then in a vacuum desiccator over NaOHpellets overnight. Product amine 3a obtained as a white powder (1.9 g).LCMS (Method 3) m/z 358.2 [MH⁺], t_(R)=19.65 min. ¹H NMR (300 MHz,DMSO-d₆): δ 8.58 (brs, 2H), 8.20 (s, 1H), 7.43 (m, 1H), 7.16-7.29 (m,7H), 5.67 (s, 2H), 4.23 (brm, 1H), 3.14 (d, J=6.9 Hz, 2H).

Step 3B:(2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide

To 1f (0.700 g, 3.3 mmol) in a 1:1 solution of DCM (2.0 mL) and DMF (2.0mL) was added N-boc-D-phenylalanine (1.3 g, 5.0 mmol) andN,N-diisopropylethylamine (0.645 g, 5.0 mmol). The reaction mixture wasstirred at room temperature for 5 minutes then HATU (1.60 g, 4.3 mmol)was added and the mixture was stirred at room temperature for 5 hours.The mixture was diluted with a saturated solution of sodium bicarbonate(100 mL) and washed with DCM (3×100 mL). The combined organic layerswere washed with a saturated solution of ammonium chloride (100 mL) thendried (Na₂SO₄) and the solvent removed under reduced pressure.Purification by silica gel column chromatography eluting with 2%MeOH/DCM gave the Boc-amine product which was then diluted with DCM (3.0mL) and stirred with 2 N HCl in ether (4.95 mL, 9.9 mmol) at roomtemperature for 1 hour. The resulting precipitate was filtered,triturated with DCM and filtered again. Drying of the filter cake underreduced pressure yielded amine 3b as a white solid (63%) (HCl salt).

LCMS (Method 3) m/z 358.2 [MH⁺], t_(R)=19.61 min.

Other compounds prepared using this procedure include:

(3S)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide,3c, LCMS (Method 3) m/z 324.2 [MH⁺], t_(R)=12.52 min.;

(3R)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide,3d, LCMS (Method 3) m/z 324.2 [MH⁺], t_(R)=12.52 min.;

(2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-methoxypropanamide,3e, LCMS (Method 3) m/z 312.2 [MH⁺], t_(R)=9.90 min. ¹H NMR (300 MHz,DMSO-d₆): δ 8.50 (brs, 1H), 8.21 (s, 1H), 7.52 (m, 1H), 7.16-7.22 (m,2H), 5.68 (s, 2H), 4.18-4.20 (m, 1H), 3.75-3.79 (m, 2H), 3.28 (s, 3H);

(2S)-2-amino-N-(1-benzyl-1H-1,2,3-triazol-4-yl)-3-methoxypropanamide,3f, LCMS (Method 4) m/z 276.1 [MH⁺], t_(R)=1.40 min.;

(2S)-2-amino-N-{1-[(3-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-methoxypropanamide,3g, LCMS (Method 4) m/z 294.1 [MH⁺], t_(R)=1.43 min.;

(2S)-2-amino-N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-methoxypropanamide,3h, LCMS (Method 4) m/z 294.1 [MH⁺], t_(R)=1.43 min.;

(2S)-2-amino-3-methoxy-N-(1-{[4-(trifluoromethyl)phenyl]methyl}-1H-1,2,3-triazol-4-yl)propanamide,3i, LCMS (Method 4) m/z 344.1 [MH⁺], t_(R)=1.62 min.;

(2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide,3j, LCMS (Method 1) m/z 298.1 [MH⁺], t_(R)=1.66 min.;

(2R)-2-amino-N-{1-[(3-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide,3k, LCMS (Method 4) m/z 280.1 [MH⁺], t_(R)=1.32 min.;(2R)-2-amino-N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide,3l, LCMS (Method 4) m/z 280.2 [MH⁺], t_(R)=1.34 min.;

(2R)-2-amino-N-(1-benzyl-1H-1,2,3-triazol-4-yl)-3-hydroxypropanamide,3m, LCMS (Method 4) m/z 262.1 [MH⁺], t_(R)=1.24 min.;

(2S)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide,3n, LCMS (Method 1) m/z 298.1 [MH⁺], t_(R)=1.72 min.;

(2S)-2-amino-N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide,30, LCMS (Method 4) m/z 280.1 [MH⁺], t_(R)=1.33 min.;

(2S)-2-amino-N-(1-benzyl-1H-1,2,3-triazol-4-yl)-3-hydroxypropanamide,3p, LCMS (Method 4) m/z 262.1 [MH⁺], t_(R)=1.25 min.; and

(2S)-2-amino-3-hydroxy-N-(1-{[4-(trifluoromethyl)phenyl]methyl}-1H-1,2,3-triazol-4-yl)propanamide,3q, LCMS (Method 4) m/z 330.1 [MH⁺], t_(R)=1.57 min.

Example 42-(1-Aminomethyl-cyclohexyl)-N-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-acetamide

Step 4A: [1-(tert-Butoxycarbonylamino-methyl)-cyclohexyl]-acetic acid

To a solution of gabapentin (2.0 g, 12 mmol) stirring in THF (10.0 mL)and H₂O (10.0 mL) was added triethylamine (4.9 mL, 36 mmol) and bocanhydride (5.2 g, 24 mmol). The reaction mixture was stirred at roomtemperature for 1 hour. The mixture was basified to pH ˜8 using aqueous2N NaOH and washed with ethyl acetate (3×100 mL). The aqueous layer wasacidified to pH ˜5 using aqueous 1 N HCL then washed with ethyl acetate(3×100 mL). The combined organic layers from the acidic wash were dried(Na₂SO₄) and the solvent removed under reduced pressure to yield[1-(tert-butoxycarbonylamino-methyl)-cyclohexyl]-acetic acid 4a as acolorless oil (90%).

Step 4B:2-(1-Aminomethyl-cyclohexyl)-N-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-acetamide

Compound 4b was prepared according to the procedure of Step 3B usingintermediate 4a instead of N-boc-D-phenylalanine. The crudeboc-protected product was purified by column chromatography with silicagel, eluting with 2% MeOH/DCM. The boc-protected product was thendiluted with DCM (3.0 mL) and stirred with 2 N HCl in ether (4.95 mL,9.9 mmol) at room temperature for 1 hour. The resulting precipitate wasfiltered, triturated with DCM and filtered again. Drying of the filtercake under reduced pressure yielded2-(1-aminomethyl-cyclohexyl)-N-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-acetamide4b as a white solid (83%) (HCl salt). LCMS (Method 3) m/z 364.3 [MH⁺],t_(R)=14.41 min.

Example 5N-[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-pyridin-4-yl-propionamide

Step 5A:N-[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-3-pyridin-4-yl-propionamide

To if (0.700 g, 3.3 mmol) in a 1:1 solution of DCM (2.0 mL) and DMF (2.0mL) was added 3-(4-pyridinyl)propanoic acid (0.755 g, 5.0 mmol) andN,N-diisopropylethylamine (0.645 g, 5.0 mmol). The reaction mixture wasstirred at room temperature for 5 minutes then HATU (1.60 g, 4.3 mmol)was added. The mixture was stirred at room temperature for 5 hours,diluted with a saturated solution of sodium bicarbonate (100 mL) andwashed with DCM (3×100 mL). The combined organic layers were washed witha saturated solution of ammonium chloride (100 mL) then dried (Na₂SO₄)and the solvent removed under reduced pressure to yield a white solid.The solid was triturated with methanol and filtered to yieldN-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-3-pyridin-4-yl-propionamide5a as a white solid (44%). LCMS (Method 3) m/z 344.2 [MH⁺], t_(R)=11.31min. ¹H NMR (300 MHz, DMSO-d₆): δ 10.97 (s, 1H), 8.46 (d, J=6.0 Hz, 2H),8.11 (s, 1H), 7.52 (m, 1H), 7.16-7.28 (m, 4H), 5.64 (s, 2H), 2.91. (t,J=7.5 Hz, 2H), 2.68 (t, J=7.5 Hz, 2H).

Other compounds made according to this procedure include:

N-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-3-pyridin-3-yl-propionamide,5b, LCMS (Method 3) m/z 344.2 [MH⁺], t_(R)=11.14 min.;

3-(3-chlorophenyl)-N-[1-(4-fluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-propionamide,5c, LCMS (Method 3) m/z 359.2 [MH⁺], t_(R)=27.39 min. ¹H NMR (300 MHz,DMSO-d₆): δ 10.90 (s, 1H), 8.18 (s, 1H), 7.18-7.43 (m, 8H), 5.54 (s,2H), 2.88 (t, J=7.5 Hz, 2H), 2.64 (t, J=7.5 Hz, 2H);

N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide,5d, LCMS (Method 4) m/z 343.1 [MH⁺], t_(R)=2.15 min.;

3-(3-chlorophenyl)-N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}propanamide,5e, LCMS (Method 4) m/z 359.1 [MH⁺], t_(R)=2.27 min.;

N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide,5f, LCMS (Method 4) m/z 325.1 [MH⁺], t_(R)=2.16 min.;

N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-(pyridin-3-yl)propanamide,5g, LCMS (Method 4) m/z 326.1 [MH⁺], t_(R)=1.49 min.; and

(2S)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-2-(2-oxopyrrolidin-1-yl)butanamide,5h, LCMS (Method 3) m/z 364.2 [MH⁺], t_(R)=18.07 min. ¹H NMR (300 MHz,DMSO-d₆): δ 8.10 (s, 1H), 7.52 (m, 1H), 7.16-7.23 (m, 7H), 5.63 (s, 2H),4.59 (m, 1H), 3.58 (m, 1H), 3.2 (m, 1H), 2.23-2.28 (m, 2H), 1.61-1.98(m, 4H), 0.82 (t, J=7.5 Hz, 3H).

Example 63-{1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1-(pyridin-3-ylmethyl)urea

Step 6A:3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1-(pyridin-3-ylmethyl)urea

To if (0.030 g, 0.14 mmol) stirring in DCM (0.5 mL) was added pyridine(0.055 g, 0.70 mmol) and triphosgene (0.038 g, 0.13 mmol). The reactionmixture was stirred in a 0° C. ice bath for 30 minutes then3-(aminomethyl)pyridine (0.075 g, 0.7 mmol) was added. The reactionmixture was stirred at room temperature overnight. Purification bypreparative HPLC-MS yielded1-[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-3-pyridin-3-ylmethyl-urea6a as a TFA salt (35%). LCMS (Method 5) m/z 345.1 [MH⁺], t_(R)=3.54 min.

Other compounds made according to the above procedure include:

3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1-(pyridin-2-ylmethyl)urea,6b, LCMS (Method 2) m/z 345.4 [MH⁺], t_(R)=2.72 min.; and

3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1-(pyridin-4-ylmethyl)urea,6c, LCMS (Method 5) m/z 345.1 [MH⁺], t_(R)=2.65 min.

Example 7

[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-carbamic acid benzylESTER

Step 7A: [1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-carbamic acidbenzyl ester

To azide 1e (0.40 g, 1.5 mmol) in DMF (3.0 mL) was added benzyl alcohol(0.486 g, 4.5 mmol). The reaction mixture was heated to 80° C. for 24hours. Upon cooling, the mixture was diluted with brine and washed withDCM (3×100 mL). The combined organic layers were dried (Na₂SO₄) and thesolvent removed under reduced pressure. Purification by columnchromatography with silica gel, eluting with 2% MeOH/DCM gave[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-carbamic acid benzylester 7a (87%). LCMS (Method 2) m/z 345.2 [MH⁺], t_(R)=5.36 min. ¹H NMR(300 MHz, CDCl₃): δ 7.92 (s, 1H), 7.15-7.57 (m, 8H), 5.63 (s, 2H), 5.14(s, 2H).

Example 8

[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine

Step 8A: [1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine

To 1f (1.5 g, 7.1 mmol) was added acetic acid (20 mL), paraformaldehyde(2.1 g, 71 mmol) and sodium cyanoborohydride (1.4 g, 21.3 mmol). Thereaction mixture was stirred at room temperature for 12 hours. Thereaction was basified with aqueous 1 N NaOH while stirring on ice andwas washed with DCM (3×200 mL). The combined organic layers were dried(Na₂SO₄), and the solvent removed under reduced pressure. Purificationby column chromatography with silica gel, eluting with 5% MeOH/DCM+0.5%TEA gave [1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine8a (35%). LCMS (Method 3) m/z 239.2 [MH⁺], t_(R)=15.82 min. ¹H NMR (300MHz, CDCl₃): δ 8.03 (s, 1H), 7.42 (m, 1H), 6.96-7.04 (m, 2H), 5.64 (s,2H), 3.21 (s, 6H).

Other compounds prepared using the above procedure include:

[1-(4-fluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine, 8b, LCMS(Method 4) m/z 221.1 [MH⁺], t_(R)=1.82 min.;

[1-(3-fluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine, 8c, LCMS(Method 4) m/z 221.1 [MH⁺], t_(R)=1.84 min.;

[1-(4-trifluoromethyl-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine,8d, LCMS (Method 4) m/z 271.1 [MH⁺], t_(R)=2.06 min.;

[1-benzyl-1H-[1,2,3]triazol-4-yl]-dimethyl-amine, 8e, LCMS (Method 4)m/z 203.1 [MH⁺], t_(R)=1.77 min.; and

1-[(2,6-difluorophenyl)methyl]-N,N-diethyl-1H-1,2,3-triazol-4-amine, 8f,LCMS (Method 1) m/z 267.0 [MH⁺], t_(R)=5.27 min. ¹H NMR (HCl salt; 300MHz, CDCl₃): δ 8.29 (brs, 1H), 7.41 (m, 1H), 7.00 (t, 2H), 5.68 (s, 2H),3.60 (m, 4H), 1.28 (m, 6H).

Example 91-[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-4-methyl-piperazine

Step 9A:1-[1-(2,6-Difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-4-methyl-piperazine

To 1f (0.030 g, 0.14 mmol) in a 2:1 solution of toluene (0.400 mL) andDMF (0.200 mL) was added mechlorethamine hydrochloride (0.025 g, 0.13mmol) and N,N-diisopropylethylamine (0.072 mg, 0.56 mmol). The reactionmixture was stirred at 100° C. for 12 hours. Purification by preparativeHPLC-MS yielded1-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-4-methyl-piperazine9a as a TFA salt (30%). LCMS (Method 2) m/z 294.3 [MH⁺], t_(R)=2.65 min.

Example 104-{1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine

Step 10A:4-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine

To a solution of amine if (1.0 g) in acetonitrile (20 mL) was addedpotassium carbonate (2 g, powdered) and 1-bromo-2-(2-bromoethoxy)ethane(1.3 g) and the reaction heated in a microwave at 120° C. for 1.5 h.Additional 1-bromo-2-(2-bromoethoxy)ethane (1.3 g) was added and heatedat 120° C. for a further 1.5 h. The mixture was filtered washing withDCM and the filtrate was concentrated and purified by chromatography onsilica gel eluting with ethyl acetate/hexane and then further purifiedby chromatography on silica gel eluting with acetone/hexane to give4-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine 10a(495 mg) as an off-white solid. LCMS (Method 1) m/z 280.9 [MH⁺],t_(R)=4.14 min. ¹H NMR (300 MHz, CDCl₃): δ 7.36 (m, 1H), 6.96 (t, 2H),6.79 (s, 1H), 5.53 (s, 2H), 3.82 (m, 4H), 3.16 (m, 4H).

Other compounds prepared using the above procedure include:

4-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine, 10b,LCMS (Method 2) m/z 263.1 [MH⁺], t_(R)=1.79 min.;

4-{1-[(3-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine, 10c,LCMS (Method 2) m/z 263.1 [MH⁺], t_(R)=1.80 min.;

4-{1-[(4-trifluoromethylphenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine,10d, LCMS (Method 2) m/z 313.1 [MH⁺], t_(R)=2.02 min.;

4-(1-benzyl-1H-1,2,3-triazol-4-yl)morpholine, 10e, LCMS (Method 2) m/z245.2 [MH⁺], t_(R)=1.74 min.; and

1-[(2,6-difluorophenyl)methyl]-4-(pyrrolidin-1-yl)-1H-1,2,3-triazole,10f, LCMS (Method 1) m/z 265.0 [MH⁺], t_(R)=5.11 min. ¹H NMR (300 MHz,CDCl₃): δ 7.35 (m, 1H), 6.96 (t, 2H), 6.71 (s, 1H), 5.51 (s, 2H), 3.27(m, 4H), 1.92 (m, 4H).

Example 111-[(2,6-Difluorophenyl)methyl]-N-methyl-1H-1,2,3-triazol-4-amine

Step 11A:N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}formamide

To a solution of amine if (1.3 g) in acetonitrile (12 mL) was addedammonium formate (5 g) and the reaction was heated in a sealed vessel at130° C. overnight. Additional ammonium formate (2 g) was added andheating continued at 130° C. for 3h. After cooling to r.t. andconcentration, water was added and the solid filtered off washing withwater to give formamide 11a (1.22 g) as a white solid. LCMS (Method 4)m/z 310.9 [MH⁺], t_(R)=2.24 min.

Step 11B:1-[(2,6-difluorophenyl)methyl]-N-methyl-1H-1,2,3-triazol-4-amine

To a solution of formamide 11a (1.22 g) in THF (40 mL) was added asolution of borane (18.5 mL, 1 M in THF) and the mixture was stirred atr.t. overnight. Methanol (20 mL) was added carefully followed by HCl (10mL, 1 N aqueous) and stirred at r.t. overnight. The reaction wasconcentrated, diluted with DCM and washed with NaOH (50 mL, 2 N aqueous)and water. The organic phase was dried over sodium sulfate, concentratedand purified by silica gel chromatography eluting with ethylacetate/hexanes to give1-[(2,6-difluorophenyl)methyl]-N-methyl-1H-1,2,3-triazol-4-amine 11b(0.67 g) as a white solid. LCMS (Method 4) m/z 225.0 [MH⁺], t_(R)=2.03min.

Example 12N-{1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}acetamide

Step 12A:N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}acetamide

To a slurry of amine 1f (1.0 g) in DCM (40 mL) was added triethylamine(0.86 mL) followed by acetyl chloride (0.37 mL) slowly with cooling inan ice bath. Warming to r.t. and concentration gave the crude amide 12a.LCMS (Method 4) m/z 252.9 [MH⁺], t_(R)=1.95 min.

Other compounds prepared using the above procedure include:

N-{1-[(3-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}acetamide, 12b, LCMS(Method 4) m/z 235.1 [MH⁺], t_(R)=1.70 min.;

N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}acetamide, 12c, LCMS(Method 4) m/z 235.1 [MH⁺], t_(R)=1.70 min.;

N-(1-{[4-(trifluoromethyl)phenyl]methyl}-1H-1,2,3-triazol-4-yl)acetamide,12d, LCMS (Method 4) m/z 285.1 [MH⁺], t_(R)=1.92 min.;

N-(1-benzyl-1H-1,2,3-triazol-4-yl)propanamide, 12e, LCMS (Method 4) m/z231.1 [MH⁺], t_(R)=1.76 min.;

N-{1-[(3-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}propanamide, 12f,LCMS (Method 4) m/z 249.1 [MH⁺], t_(R)=1.81 min.; and

N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}propanamide, 12g,LCMS (Method 4) m/z 249.1 [MH⁺], t_(R)=1.81 min.

Step 12B:1-[(2,6-difluorophenyl)methyl]-N-ethyl-1H-1,2,3-triazol-4-amine

To a slurry of the crude amide 12a in THF (20 mL) was added LithiumAluminum Hydride (1 M in THF, 8.3 mL) and the mixture was stirred at r.tfor 3 days. The reaction was quenched by addition of Rochelle's salt(saturated aqueous) and extracted with ethyl acetate (2×100 mL). Theorganic phase was extracted with HCl (1 N, aqueous) and the organicdiscarded. The aqueous phase was basified with NaOH (2 N, aqueous) to pH8 and the product extracted into ethyl acetate (2×30 mL). The organicwas washed with brine, dried over magnesium sulfate and concentrated togive 1-[(2,6-difluorophenyl)methyl]-N-ethyl-1H-1,2,3-triazol-4-amine_12h as a white solid. LCMS (Method 4) m/z 211.0 [MH⁺], t_(R)=2.11 min.

Example 132-({1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}amino)ethan-1-ol

Step 13A:({1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}carbamoyl)methylacetate

To a slurry of amine 1f (1.3 g) in DCM (40 mL) was added triethylamine(1.1 mL) followed by acetoxyacetyl chloride (0.73 mL) slowly at r.t. andstirred for 1 h. After washing with saturated sodium bicarbonate andwater the organic was dried over sodium sulfate and concentrated to give({1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}carbamoyl)methylacetate 13a (1.9 g) as a white solid. LCMS (Method 4) m/z 310.9 [MH⁺],t_(R)=2.24 min.

Step 13B:2-({1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}amino)ethan-1-ol

To a slurry of amide 13a (1.9 g) in THF (40 mL) was added a solution ofborane (18.5 mL, 1 M in THF) and refluxed for 8 h. Methanol (20 mL) wasadded carefully followed by HCl (6 N, aqueous) and the mix was stirredat 60° C. overnight. After cooling the mixture was concentrated, dilutedwith DCM and washed with NaOH (50 mL, 2 N aqueous) and water. Theorganic phase was dried over sodium sulfate, concentrated and purifiedby silica gel chromatography eluting with ethyl acetate/hexanes to give2-({1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}amino)ethan-1-ol13b (0.91 g) as a white solid. LCMS (Method 4) m/z 254.9 [MH⁺],t_(R)=1.92 min.

Example 141-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}pyrrolidin-2-one

Step 14A:1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}pyrrolidin-2-one

To a solution of amine if (400 mg) in DCM (8 mL) was added DIEA (0.41mL) followed by 4-chlorobutanoyl chloride (0.23 mL) and the mixture wasstirred at r.t. overnight. The reaction mixture was dried down and DMF(2 mL) was added and the reaction dried down again and then re-dissolvedin DMF. NaH (169 mg, 60% in oil) was added with stirring and thereaction heated at 60° C. overnight. Extra NaH (60 mg, 60% in oil) wasadded and heated at 60° C. overnight again to complete the reaction. DCMand ammonium chloride were added and the organic was separated and driedover magnesium sulfate and concentrated. Chromatography on silica geleluting with ethyl acetate/hexane gave the lactam1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}pyrrolidin-2-one14a (230 mg) as a white solid. LCMS (Method 1) m/z 279.1 [MH⁺],t_(R)=4.50 min. ¹H NMR (300 MHz, CDCl₃): δ 8.13 (s, 1H), 7.35 (m, 1H),6.96 (t, J=7.0 Hz, 2H), 5.60 (s, 2H), 4.07 (t, J=7.8 Hz, 2H), 2.55 (t,2H), 2.21 (app qn, J=7.4 Hz, 2H).

Example 153-{1-[(2,6-Difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-oxazolidin-2-one

Example 15A3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1,3-oxazolidin-2-one

To a solution of crude amine 13b (1.3 g, without purification) in DCM(100 mL) was added triethylamine (1.8 mL) followed by triphosgene (0.65g). The mixture was stirred at r.t. overnight. Additional triphosgene(0.06 g) was added and stirred overnight. The reaction was washed withwater, saturated sodium bicarbonate, dried over sodium sulfate andconcentrated. Chromatography on silica gel eluting with ethylacetate/hexane gave carbamate3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1,3-oxazolidin-2-one15a (0.65 g) as a white solid. LCMS (Method 1) m/z 281.1 [MH⁺],t_(R)=4.36 min. ¹H NMR (300 MHz, CDCl₃): δ 7.91 (s, 1H), 7.38 (m, 1H),6.97 (t, 1H), 5.62 (s, 2H), 4.56 (t, 2H), 4.23 (t, 2H).

Example 161-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}imidazolidin-2-one

Step 16A:1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}imidazolidin-2-one

To a solution of amine if (5.0 g, 23.8 mmol) and Boc-glycine (5.0 g,28.6 mmol) in DCM (40 mL) and DMF (40 mL) was added DIEA (6.2 mL)followed by HATU (12.7 g) and the mixture was stirred at r.t. for 3days. The reaction was concentrated to remove DCM and excess water wasthen added. The solid was filtered off washing with water and driedunder vacuum to give the amide as an off-white solid (8.6 g). The amideproduct was dissolved in DCM (40 mL) and HCl (4 M in dioxane, 40 mL) wasadded and stirred at r.t. for 1 h. NaOH (4 M aqueous) was addedcarefully to basify and additional DCM added. The organic layer wasdried over magnesium sulfate and concentrated to give the crude amine.The amine was dissolved in THF (20 mL) and borane (1 M in THF, 72 mL)was added and the solution was heated at 60° C. for 16 h. At 60° C. withrapid stirring MeOH (20 mL) was added carefully followed by HCl (4 M indioxane, 35 mL) carefully and then refluxed for 1.5 h. The reaction wascooled, concentrated (approx. 80% solvent removed) and ether was addedto precipitate the diamine as the HCl salt. The product was filteredunder a stream of nitrogen washing with ether and dried by suction undera nitrogen stream to give a white solid (6.95 g, assumed di-HCl salt).The diamine (6.95 g) was dissolved in DCM (200 mL) containing excessDIEA (15 mL) and triphosgene (2.12 g in 50 mL DCM) was added slowly atr.t. After 1 h the reaction mixture was washed with HCl (1 M aqueous,2×50 mL), NaOH (2 M aqueous, 50 mL), water and brine, and washed driedover magnesium sulfate and concentrated to give a white solid. The solidwas re-dissolved in DCM (minimum amount to dissolve) and precipitated byaddition of ether. The solid was filtered off washing with ether to give1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}imidazolidin-2-one16a (3.45 g) as a white solid. LCMS (Method 1) m/z 280.0 [MH⁺],t_(R)=3.42 min. ¹H NMR (300 MHz, CDCl₃): δ 7.95 (s, 1H), 7.50 (m, 1H),7.18 (t, 2H), 7.07 (s, 1H), 5.62 (s, 2H), 3.87 (t, 2H), 3.43 (t, 2H).

Example 17 Maximal Electroshock Test

All animal model experiments described herein were performed in malerodents (albino Carworth Farms No. 1 (CF-1) mice, or albinoSprague-Dawley rats). Housing, handling, and feeding were in accordancewith recommendations contained in the ‘Guide for the Care and Use ofLaboratory Animals’. Many of the following experiments were performed bythe Anticonvulsant Screening Program (ASP) of the National Institute ofNeurological Diseases and Stroke. The Department of Health and HumanServices recently expanded the scope of the ASP to include countermeasures for exposure to nerve agents.

In vivo antiseizure activity was measured by the maximal electroshock(MES) test. Adult male CF-1 albino mice (18-25 g) or Sprague-Dawley rats(100-150 g) were utilized for these experiments. An alternating currentof 60 Hz (50 mA in mice, 150 mA in rats) was delivered for 0.2 sec bycorneal electrodes which had been primed with an electrolyte solutioncontaining 0.5% tetracaine HCl anesthetic. The endpoint for protectionfrom MES-induced seizures is the abolition of the hindlimb tonicextensor component of the seizure. Mice were tested at various timeintervals following doses of test compound given by intraperitonealadministration using a volume of 0.01 ml/g in mice, and rats werescreened with 0.04 ml/g (both i.p. and p.o.). The compounds listed inTable 1 were shown to be active at the single dose stated, or with anED₅₀ if multiple doses were tested (data are for mice administered i.p.and for rat administered p.o., mpk=mg/kg).

TABLE 1 Compound Mouse (IP) Rat (PO) 3a MES active at 100 mpk MES ED₅₀25 mpk 3b MES ED₅₀ 56 mpk MES ED₅₀ 24 mpk 3c MES ED₅₀ 20 mpk MES activeat 15 mpk 3d MES ED₅₀ 73 mpk MES ED₅₀ 24 mpk 3e MES ED₅₀ 40 mpk MESactive at 30 mpk 3j  MES active at 100 mpk MES ED₅₀ 29 mpk 5b MES activeat 300 mpk — 5e MES active at 100 mpk — 5h MES active at 300 mpk — 8aMES ED₅₀ 27 mpk MES ED₅₀ 9 mpk 8e MES active at 100 mpk — 10a  MES ED₅₀31 mpk MES ED₅₀ 44 mpk 10f   MES ED₅₀ 73 mpk MES active at 30 mpk 11b MES active at 100 mpk MES active at 30 mpk 12h  MES active at 100 mpkMES active at 30 mpk 13b  MES active at 30 mpk MES active at 30 mpk 14a MES active at 100 mpk MES ED₅₀ 28 mpk 16a  MES ED₅₀ 8 mpk MES ED₅₀ 7 mpk

Example 18 Subcutaneous Metrazol Seizure Threshold Test

Animals are pretreated with various doses of test compound as for theMES tests. The dose of metrazol which induced convulsions in 97% ofcontrol animals (85 mg/kg in mice) is injected into a loose fold of skinin the midline of the neck. To minimize stress, animals are placed inisolation cages and observed for the next 30 min for the presence orabsence of a seizure. Continuous observation allows the time to peakeffect (TPE) for each drug to be determined. An episode of clonicspasms, lasting approximately 3-5 s, of the fore- and/or hindlimbs, jawsor vibrissae is taken as the endpoint. Animals that do not meet thiscriterion are considered protected.

Example 19 Acute Toxicity—Minimal Motor Impairment

Animals are monitored for overt signs of impaired neurological ormuscular function. In mice, the rotorod test is used. An untreatedmouse, when placed on a rod that rotates at a speed of 6 rpm, canmaintain its equilibrium for long periods of time. The test compound areconsidered toxic if the mouse falls off this rotating rod three timesduring a 1-min period. In rats, minimal motor deficit was indicated byataxia (manifested by an abnormal, uncoordinated gait). In addition tominimal motor impairment, the animals are observed for other abnormalsigns including abnormal body posture, tremors, hyperactivity, lack ofexploratory behavior, or somnolence. Dose response curves for toxicitycan be produced in order for a dose toxic in 50% of animals (TD₅₀) to bedetermined.

Example 20 Chemoconvulsant-Induced Seizures

The test compound is given at or below the TD₅₀ dose and tested at thes.c. metrazol time of peak effect (TPE). This test measures the abilityof the test substance to prevent a clonic seizure produced by the s.c.injection of either bicuculline (2.7 mg/kg) or picrotoxin (2.5 mg/kg).Following the administration of bicuculline, CF-1 mice are placed inisolation cages and observed for 30 min for the presence or absence of aseizure; those receiving picrotoxin are observed for 45 min because ofthe slower absorption of this convulsant. Seizures typically consistedof an episode of clonic spasms of the fore- and hind limbs, jaws andvibrissae. Bicuculline-induced clonic seizures are generally followed bytonic extension of the hind limbs and death. The compound is consideredprotective if there was an absence of a seizure for the entireobservation period,

Example 21 Minimal Clonic Seizure Test

Twenty CF-1 mice are pretreated with 30, 100 and 300 mg/kg test compoundi.p. At varying times (0.25, 0.5, 1, 2, and 4 h) after treatment,individual mice (four at each time point) are administered eye drops of0.5% tetracaine hydrochloride, and challenged with sufficient current(32 mA at 6 Hz for 3 s) delivered through corneal electrodes to elicit apsychomotor seizure. In general, this seizure is characterized by aminimal clonic phase, followed by stereotypy and automatistic behaviorsdescribed originally as being similar to the aura of human patients withpartial seizures (Toman, Neurology, 1951. 1:444-460). Animals notdisplaying this behavior are considered protected.

Example 22 Hippocampal-Kindled Rat Test (Focal Seizures)

Electrodes are implanted into the hippocampus of anesthetized rats,which are then allowed to recover for 1 week. Following the rapidkindling protocol (Lothman et al., Brain Res., 1994. 649:71-84), therats are stimulated with 200 mA for 10 s, 50 Hz, every 30 min for 6 h onalternate days until they are fully kindled (4-5 stimulus days). After 1week of rest, the animals are given the same electrical stimulus, whichserved as a baseline. The animals are pretreated with the test compound(by i.p. injection) and then tested at various intervals. At each timepoint, the behavioral seizure score and after-discharge duration arerecorded. The behavioral seizure scores are scored according to thefollowing criteria (Racine, Electroencephalogr Clin Neurophysiol, 1972.32(3):281-94): stage 1—mouth and facial clonus; stage 2—stage 1 plushead nodding; stage 3—stage 2 plus forelimb clonus; stage 4—stage 3 plusrearing, and stage 5—stage 4 plus repeated rearing and falling. Theafter-discharge threshold (ADT) can also be measured in the kindled rat.The ADT is defined as the lowest current at which an after-discharge ofat least 4 s is elicited. On the day of the test, the individual ADT ofeach rat is determined by increasing the current intensity in a stepwisefashion until the rat displayed an electrographic after-discharge withduration of at least 4 s. The initial stimulation is conducted at anintensity of 20 μA with 10 μA increments every 1-2 min until anafter-discharge was elicited. Fifteen minutes after the predrugthreshold determination, a single dose of the test substance isadministered to 2 animals in a volume of 0.04 ml/10 g body weight. Inthis way, the animals serve as their own control. The individual rat ADTis then determined at varying times (i.e., 0.25, 1, 2 and 4 h) afterdrug administration. Results of this assay are presented in Table 2.

TABLE 2 Compound Rat 3a active at 200 mpk 3c active at 50 mpk 3d ED₅₀ 79mpk 8a ED₅₀ 25 mpk 10a  ED₅₀ 32 mpk 16a  active at 100 mpk

Example 23 In Vitro Spontaneous Bursting Model of Pharmacoresistance

Systemic Kainate (KA) Treatment: KA treatment consists of multiplesystemic injections of KA in a modified protocol as previously described(Hellier, et al., Epilepsy Research, 1998. 31:73-84). Sprague-Dawleyrats are removed from their home cages, weighed, and placed individuallyinto Plexiglass tubs for injections and monitoring. Seizures are scoredduring the experiment based on the Racine scale (Racine,Electroencephalogr Clin Neurophysiol, 1972. 32(3):281-94). Vehicle (0.9%saline) or KA (5 mg/kg, i.p.) is administered once every hour untilanimals begin to exhibit behaviors consistent with early stage seizures(Stage 1-3). Once an animal has begun to seize, dosing is ceased orreduced to 2.5 mg/kg (i.p.) for that animal until at least one Stage 4/5seizure per hour is observed. The number and stage of seizures isrecorded until the animal has exhibited Stage 4 or Stage 5 seizures for3.5 hours. Animals not having at least one Stage 4 or 5 seizure per hourare not included in the analysis. After 3.5 hours of monitoring, ratsare given an i.p. injection of 0.9% saline (1-2 mL) for hydration andreturned to their home cages. The combined entorhinal cortex/hippocampalslice is obtained from the rats under anesthesia with pentobarbitol (35mg/kg). Following rapid decapitation, the brains are removed and placedfor one minute in an ice-cold, oxygenated (95% O₂/5% CO₂), Ringer'ssolution containing, (in mM): Sucrose (125.0), KCl (3.0), NaH₂PO₄ (1.2),MgSO₄ (2.0), NaHCO₃ (26.0), glucose (10.0), and CaCl₂ (2.0) (Scharfman,J Neurophysiol, 1997. 78(2):1082-95). The brains are then blocked andglued, cortex down, to the chuck of a vibratome. Horizontal sections(400 μm) containing the entorhinal cortex and hippocampus are taken andplaced in a holding chamber for at least one hour before commencingrecording. The oxygenated Ringer's solution in the holding chamber, andfor recording, has NaCl (126 mM) instead of sucrose, pH=7.4 andosmolarity of 300-310 mOsm.

Extracellular field potential recordings (at 31±1° C.) are made in LayerII of the medial entorhinal cortex (mEC) with borosilicate glasselectrodes (3-6 MΩ) filled with normal Ringer solution or 3M NaCl. Aconcentric bipolar stimulating electrode placed in the angular bundle isused to elicit field potential responses. Signals are filtered at 3 kHz,sampled at 10 kHz, and acquired for computer storage using a Digidata1440A AD Converter (Axon Instruments). Stimulus input/output (I/O)curves are determined to establish stable baseline responses and todetermine threshold and maximal responses. Voltage pulses of 1-20 V aretriggered using a stimulus isolator unit. Only slices that generatestable I/O responses throughout the baseline recording period areaccepted. The extracellular solution is then switched to one containing6 mM KCl and 0.1 mM Mg²⁺ in order to elicit spontaneous, electrographicburst activity (SB).

Results obtained with the investigational substance are compared tothose results obtained with “traditional” (e.g., phenytoin,carbamazepine) and “non-traditional” (e.g., retigabine) anticonvulsants.The dependent variables that are measured include frequency and durationof bursts in the presence and absence of AEDs. Compounds (100 μM) foundto substantially block the spontaneous bursting at this concentrationare considered efficacious. Results are compared by Student's t-testwith statistical significance defined as p<0.05.

Example 24 Lamotrigine (LTG)-Resistant Amygdala-Kindled Rat Model

Two groups (LTG and vehicle-treated, n=8-10 rats/group) of maleSprague-Dawley rats (250-300 g) are stereotactically implanted with anelectrode in the left amygdala (AP+5.7 mm, ML+4.5, DV+2.0 fromintra-aural zero) under ketamine-xylazine anesthesia. Animals are thenallowed to recover for one week before commencing kindling (Postma etal., Epilepsia, 2000. 41:1514-21). One hour prior to the kindlingstimulation, rats receive a single i.p. dose of either vehicle (0.5%methylcellulose (MC)) or LTG (5 mg/kg in 0.5% MC). The kindlingprocedure consists of delivering a 200 μAmp stimulus (suprathreshold)daily until all animals in both treatment groups display consistentStage 4 or 5 seizures, as scored by the Racine rating scale. One weekafter all animals are kindled, the animals receive a challenge dose ofLTG (15 mg/kg, i.p.) before being stimulated to confirm the LTGsensitivity of the vehicle-treated control animals, as well as theLTG-resistance of the LTG-treated group. The animals are then allowed awashout of 3 days. On day 3 of the washout, the animals arepre-stimulated to ensure recovery of the fully kindled seizure. On day4, rats in both treatment groups are challenged with a single dose of aninvestigational AED (the dose that produced minimal motor impairment(MMI)). Rats in both treatment groups are then challenged with thekindling stimulus at the predetermined TPE of the investigational AED.When a drug treatment is observed to significantly lower seizure scoreand decrease afterdischarge, a dose-response study can be conducted. Forthis study, the ability of a candidate substance to reduce theafterdischarge duration (ADD) and seizure severity is quantitated byvarying the dose between 0 and 100% effect. Results are expressed as thenumber of animals protected (i.e., not displaying a secondarilygeneralized limbic seizure) over the number of animals tested. Theseizure score is analyzed by Mann-Whitney U-test and the ADD (±S.E.M.)is analyzed by Student's t-test, with p<0.05 determined to bestatistically significant. The median effective dose and 95% confidenceinterval is then calculated by probit analysis.

Example 25 Focal Seizures in Corneal-Kindled Mice

Adult male CF-1 mice (n=8 per group, 18-25 g) are kindled to a criterionof 5 consecutive secondarily generalized seizures (Racine stage 4 or 5,according to the corneal kindling protocol previously described (Rowleyet al., Epilepsy Res, 2010. 92(2-3): 163-69; Matagne et al., EpilepsyRes, 1998. 31(1):59-71). Twice daily, a 0.5% tetracaine hydrochloridesolution is applied to each eye and the optic nerve is stimulatedthrough corneal electrodes (3 mA, 60 Hz, 3 seconds). After receivingtwice daily corneal stimulations, CF-1 mice typically reach the firstStage 5 seizure between approximately days 10-14. Twice dailystimulations continue for each mouse until that mouse has achieved thecriterion of 5 consecutive stage 5 seizures, whereby it is considered“fully kindled”. Fully kindled mice are then stimulated every-other toevery 3 days until all other mice within the group reach the criterionof 5 consecutive Stage 5 seizures. Testing of investigational compoundscommences at least 5-7 days after receiving the last stimulation. Foridentification studies 100 mg/kg, of the test compound is administeredi.p. to five groups of 4 fully kindled mice per group. Mice in eachgroup are then tested at various time points (0.25, 0.5, 1, 2, 4 hours)after drug dosing. Mice displaying a seizure score <3 are consideredprotected. The time point with the most animals protected is consideredthe time of peak effect (TPE) of the investigational compound.Quantitative differentiation studies may also be performed at the TPE.At least 3 doses, sufficient to produce between 0%-100% protection aspreviously determined in the above described identification studies, areevaluated in groups of 8-10 fully kindled mice. After testing, thecorneal-kindled animals are returned to their home cage, and allowed atleast 3-4 days between tests to “washout” any investigational compoundafter testing. The ability of an investigational drug to block the fullykindled behavioral seizure is suggestive of activity against secondarilygeneralized partial seizures. For quantification of protection in thecorneal kindling model, the effective dose at which 50% of mice areprotected (ED₅₀), the 95% confidence interval (95% C.I.), and theslope+S.E.M. are calculated using probit analysis.

Example 26 Pilocarpine Rat Model

Compounds are assessed for their ability to halt pilocarpine-inducedconvulsive status epilepticus (SE). To identify doses of drug to be usedin the SE testing, acute motor impairment is assessed following theintraperitoneal (i.p.) administration of doses starting at 100 and 300mg/kg. Individual Sprague Dawley rats are evaluated for acute toxicityover several time points following administration of test compounds. Theresults obtained from this initial study determine whether any doseadjustments are required. The behavior of the animals is observedclosely and recorded over a four hour period. Routinely, a minimumnumber of four rats, two per dose are employed in this acute screen.

To determine if the test substance can halt acute pilocarpine-inducedstatus an initial qualitative efficacy screen is performed. A challengedose of pilocarpine (50 mg/kg) is administered i.p. and animals observeduntil the first convulsive (e.g., Stage 3, 4, or 5) seizure (time zero).The seizure severity is determined using the Racine scale. At this pointa minimally toxic dose of the candidate drug is administered to a groupof 8 male albino Sprague Dawley rats (150-180 g) via the i.p. route ofadministration. Efficacy is defined by the ability of an investigationaldrug to halt the further expression of pilocarpine induced convulsiveseizures (e.g., Stage 3, 4, or 5). Compounds found to possesssignificant protection at time zero (time from the first stage 3, 4, or5 seizure) may proceeded to further evaluation in the sustained statusmodel. In this test, the investigational drug is administered 30 minutesafter the first observed convulsive seizure. This is a more severe testof a candidate's ability to halt the induced status. Compounds found topossess significant activity may be advanced for quantification whereinthe ED₅₀ and TD₅₀ and corresponding 95% confidence intervals aredetermined. A minimum of 4 doses with at least 8 rats per dose areutilized in the quantification study.

The compounds of Table 3 were tested in the pilocarpine assay (initialqualitative efficacy screen) and showed activity at the dose shown whenadministered after seizure onset (mpk=mg/kg).

TABLE 3 Compound Dose 3a 200 mpk 3d 450 mpk 8a  65 mpk 10a   65 mpk10f    65 mpk

Example 27 Frings Audiogenic Seizure (AGS) Susceptible Mice

Male and female Frings audiogenic seizure-susceptible mice (18-25 g) areused in this study. For each screening test, groups of 8 mice each aretreated i.p. with varying doses of the investigational compound. At thetime of peak effect as determined in the MES test (in CF-1 mice),individual mice are placed in a round plexiglass jar (diameter, 15 cm;height, 18 cm) and exposed to a sound stimulus of 110 decibels (11 kHz)delivered for 20 sec. Mice are observed for 25 sec for the presence orabsence of hind limb tonic extension. Mice not displaying hind limbtonic extension are considered protected. The severity of a seizure mayalso be quantitated by assigning a numerical score to the observedresponse, e.g., no response—0; wild running for <10 sec—1; wild runningfor >10 sec—2; clonic seizure—3; forelimb extension/hind limb flexion—4;tonic seizure—5. The ability of a test substance to block audiogenicseizures can be quantitated by results collected from different doseswith protection between 0% and 100% used to calculate an ED₅₀. Theanticonvulsant activity of those test substances that afford protectionin this model is quantitated and the ED₅₀ and the 95% confidenceinterval calculated by probit analysis.

Example 28 Soman Rat Model

Rats are surgically prepared with cortical electrodes to record brainelectroencephalographic (EEG) activity one week prior to testing. On theday of test, the animals are attached to the recording equipment and EEGis recorded continuously. After baseline recording, the animals arepretreated with the oxime HI-6 (125 mg/kg, i.p.) to reduce the immediatelethal effects of nerve agent challenge. Thirty min after HI-6, theanimals are challenged with 180 μg/kg (s.c.) of the nerve agent somanand 1 min later they were administered 2.0 mg/kg atropine methyl nitrate(i.m.). This treatment regimen elicits continuous seizure activitywithin 5-8 min after soman challenge in 100% of animals tested. Both EEGand neuropathological techniques are used to assess the effectiveness ofanticonvulsant treatment. At progressively longer treatment delay times(5 min, 20 min or 40 min) after seizure onset animals are administeredstandard medical countermeasures (0.45 mg/kg atropine sulfate admixedwith 25 mg/kg 2-PAM, 2.2 mg/kg diazepam) along with the adjunct testdrug. Dose-effect curves for anticonvulsant effectiveness aredetermined.

Example 29 Harmaline-Induced Tremor Assay

The harmaline-induced tremor assay is the primary preclinical model ofinduced tremor. Male ICR mice (10 weeks old) were used in this study.Mice were group housed in OPTI mouse ventilated cages. All animalsremained group housed during the duration of the study. All mice wereacclimated to the colony room for at least one week prior to testing.During the period of acclimation, mice were examined on a regular basis,handled, and weighed to assure adequate health and suitability. Micewere maintained on a 12/12 light/dark cycle. The room temperature wasmaintained between 20 and 23° C. with a relative humidity maintainedbetween 30% and 70%. Chow and water were provided ad libitum for theduration of the study. In each test, animals were randomly assignedacross treatment groups.

Ten mice were tested in each group. All compounds were administered byoral gavage at a dose volume of 10 mL/kg:

Harmaline (30 mg/kg) was prepared in sterile saline and administeredsubcutaneously.

Propranolol HCl (10 mg/kg) was dissolved in sterile saline andadministered i.p. 20 minutes prior to harmaline.

Test compounds were suspended in 0.5% methylcellulose and administeredi.p. 20 minutes prior to harmaline.

Group housed mice were brought to the experimental room for at least 1 hacclimation prior to testing. Mice were injected with either sterilevehicle, propranolol, or test compound and placed in separate holdingcages for 20 minutes following which mice were injected with harmaline(30 mg/kg) and placed inside the Tremor Monitor (San Diego Instruments,SDI) chamber for a 10 minute acclimation period. After habituation,tremor activity of the mice was measured for approximately 8 min. Therecorded frequencies (1-64 Hz) of activity and the number of tremorevents were captured electronically.

Data were analyzed by the tremor monitor software (San DiegoInstruments) in a two part process. Using a Fast Fourier Transform(FFT), an output is provided showing the percentage of activity (energy)recorded at each frequency. A center frequency of activity between 14-15Hz is chosen, along with a bandwidth of 10 Hz. Using these parameters,tremor events were tabulated as short, long, and total events. A longevent is defined as being greater than 0.5 seconds in duration, and ashort event as between 0.3 and 0.5 seconds in duration.

Data were analyzed by analysis of variance (ANOVA) followed by FisherPLSD post-hoc analysis. An effect was considered significant if p<0.05.Statistical outliers that fell above or below 2 standard deviations fromthe mean in any of the three measures (short, long or total tremorevents) were removed from the final analysis.

The compounds listed in Table 4 were tested in the harmaline assay andshowed significant reductions in total tremors at the oral doses noted(mpk=mg/kg).

TABLE 4 Compound Dose  8a 50, 150 mpk 10a 5, 15, 50, 150 mpk 11b 15, 50mpk 14a 50 mpk 15a 50 mpk 16a 50, 150 mpk

The various embodiments described above can be combined to providefurther embodiments. All U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications, and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

We claim:
 1. A compound having the following structure (A):

or a stereoisomer, ester, solvate, or pharmaceutically acceptable saltthereof, wherein: R₁ is H or C₁₋₄alkyl; R₂ is C₁₋₄alkyl, —C(═O)OR₄,—C(═O)—C₁₋₆alkanediyl-NH₂, —C(═O)NR₅R₅, or —C(═O)R₆, wherein saidC₁₋₆alkanediyl is optionally substituted with a group selected from—NH—C(═NH)NH₂, —CO₂H, —CO₂CH₃, —SH, —C(═O)NH₂, —SCH₃, phenyl, —OH,—OC₁₋₄alkyl, 4-hydroxy-phenyl, imidazolyl, cyclohexyl, and indolyl; orR₁ and R₂ taken together with the N to which they are attached, form a5-6 member nonaromatic heterocycle wherein the 5-6 member nonaromaticheterocycle may be substituted with 0-3 R₄; R₃ at each occurrence is Cl,F, C₁₋₄alkyl, —OC₁₋₄alkyl or trifluoromethyl; R₄ at each occurrence isC₁₋₄alkyl; R₅ at each occurrence is independently H or C₁₋₄alkyl; R₆ isC₁₋₄alkyl, 5-6 member nonaromatic heterocycle, or 5-6 memberheterocycleC₁₋₄alkyl wherein 5-6 member heterocycleC₁₋₄alkyl isoptionally substituted with OH, Cl, F, C₁₋₄alkyl, —OC₁₋₄alkyl ortrifluoromethyl; and n is 0-3.
 2. The compound of claim 1, wherein nis
 1. 3. The compound of claim 1, wherein n is
 2. 4. The compound ofclaim 1, wherein R₁ is H.
 5. The compound of claim 1, wherein R₁ isC₁₋₄alkyl.
 6. The compound of claim 1, wherein R₂ is C₁₋₄alkyl,—C(═O)OR₄, —C(═O)NR₅R₅, or —C(═O)R₆.
 7. The compound of claim 1, whereinR₂ is C₁₋₆alkanediyl, optionally substituted with a group selected from—NH—C(═NH)NH₂, —CO₂H, —CO₂CH₃, —SH, —C(═O)NH₂, —NH₂, —SCH₃, phenyl, —OH,—OC₁₋₄alkyl, 4-hydroxy-phenyl, cyclohexyl, imidazolyl, and indolyl. 8.The compound of claim 1, wherein R₁ and R₂ are both C₁₋₄alkyl.
 9. Thecompound of claim 1, wherein R₃ is Cl, F, or trifluoromethyl.
 10. Thecompound of claim 1, wherein R₃ is C₁₋₄alkyl or —OC₁₋₄alkyl.
 11. Thecompound of claim 1, wherein n=1 or 2 and R₃ is F.
 12. The compound ofclaim 1, wherein R₆ is C₁₋₄alkyl.
 13. The compound of claim 1, whereinR₆ is a 5-6 member nonaromatic heterocycle.
 14. The compound of claim 1,wherein R₆ is a 5-6 member heterocycleC₁₋₄alkyl wherein 5-6 memberheterocycleC₁₋₄alkyl is optionally substituted with OH, Cl, F,C₁₋₄alkyl, —OC₁₋₄alkyl or trifluoromethyl.
 15. The compound of claim 1,wherein R₁ and R₂ are taken together to form a heterocycle, and thecompound has the following structure (B):


16. The compound of claim 15, wherein n is
 1. 17. The compound of claim16, wherein R₃ is F.
 18. The compound of claim 15, wherein n is
 2. 19.The compound of claim 18, wherein R₃ at each occurrence is F.
 20. Thecompound of claim 15, wherein R₃ is C₁₋₄alkyl, —OC₁₋₄alkyl,trifluoromethyl, or Cl.
 21. The compound of claim 15, wherein theheterocycle formed by R₁ and R₂ taken together is piperidine.
 22. Thecompound of claim 15, wherein the heterocycle formed by R₁ and R₂ takentogether is morpholine.
 23. The compound of claim 15, wherein theheterocycle formed by R₁ and R₂ taken together is piperazine,oxazolidine, or pyrrolidine.
 24. The compound of claim 15, wherein R₄ ismethyl or ethyl.
 25. The compound of claim 1, wherein the compound isone of the following, compounds, or a pharmaceutically acceptable saltthereof: (2S)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide;(2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide;(3S)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide;(3R)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide;(2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-methoxypropanamide;(2R)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-hydroxypropanamide;N-[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-3-pyridin-3-yl-propionamide;3-(3-chlorophenyl)-N-{1-[(4-fluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}propanamide;(2S)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-2-(2-oxopyrrolidin-1-yl)butanamide;[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine;[1-benzyl-1H-[1,2,3]triazol-4-yl]-dimethyl-amine;4-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine;1-[(2,6-difluorophenyl)methyl]-4-(pyrrolidin-1-yl)-1H-1,2,3-triazole;1-[(2,6-difluorophenyl)methyl]-N-methyl-1H-1,2,3-triazol-4-amine;1-[(2,6-difluorophenyl)methyl]-N-ethyl-1H-1,2,3-triazol-4-amine;2-({1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}amino)ethan-1-ol;1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}pyrrolidin-2-one;or3-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-1,3-oxazolidin-2-one;or1-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}imidazolidin-2-one.26. The compound of claim 1, wherein the compound is(2S)-2-amino-N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}-3-phenylpropanamide.27. The compound of claim 1, wherein the compound is(3R)—N-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine-3-carboxamide.28. The compound of claim 1, wherein the compound is[1-(2,6-difluoro-benzyl)-1H-[1,2,3]triazol-4-yl]-dimethyl-amine.
 29. Thecompound of claim 1, wherein the compound is4-{1-[(2,6-difluorophenyl)methyl]-1H-1,2,3-triazol-4-yl}morpholine. 30.The compound of claim 1, wherein the compound is1-[(2,6-difluorophenyl)methyl]-4-(pyrrolidin-1-yl)-1H-1,2,3-triazole.31. A pharmaceutical composition comprising a compound of claim 1, or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier or diluent.
 32. A method for treating a neurologicalcondition of a subject in need thereof, comprising administering to thesubject an effective amount of a compound of claim 1 or apharmaceutically acceptable salt thereof.
 33. A method for treating aneurological condition of a subject in need thereof, comprisingadministering to the subject an effective amount of a pharmaceuticalcomposition of claim
 31. 34. The method of claim 33, wherein thecondition is essential tremor, epilepsy, status epilepticus, or nerveagent exposure.
 35. The method of claim 34, wherein the condition isessential tremor.